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SCERT AP Board 9th Class Social Solutions 16th Lesson Social Protest Movements Textbook Questions and Answers.

AP State Syllabus 9th Class Social Studies Solutions 16th Social Protest Movements

9th Class Social Studies 16th Lesson Social Protest Movements Textbook Questions and Answers

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Question 1.
Which of the following statements about lives of industrial workers are correct? And correct the false statements.
a) Workers controlled the industries.
b) Living conditions of the workers were comfortable.
c) Low wages was ones of the reasons for discontent among the workers.
d) During the phase of industrialization there was emphasis on emotions and feelings.
e) Romantic writers and artists tried to highlight values of closeness to nature as described in the folk tales and folk songs.
Answer:
a) False
b) False
c) True
d) False
e) True
Correction of false statements :
a) Workers did not control the industries.
b) Living conditions of the workers were not comfortable.
d) Duringthe phase of industrialization there was no emphasis on emotions and feelings.

Question 2.
List some of the problems faced by workers of those times. Discuss if such problems exist in our times too.
Answer:

• The workers were under the control of unsympathetic foreman and managers.
• There was no security for their lives and they lost their jobs. Working hours were long and unbroken.
• Wages were meagre and frequently owners tried to cut down wages or retrench workers or increase work load on them.
• The lifespan of the workers decreased.
• Workers were prone to accidents and no compensations were given.
• Workers used to live in slums and deaths were caused by spread of diseases.
• Children were taken as child labour in risky coal mines.

Present condition of workers :

• Salaries or wages are regularized.
• Factory regulation act prohibited children in coal mines. Later child labour is now prohibited.
• Working conditions are improved.
• Compensations are paid for accidents or deaths but it is very less.

Question 3.
Write a paragraph comparing the ideas of capitalism and socialism. How were they similar or different?
(OR)
Distinguish between socialism and capitalism.
(OR)
Compare and contrast between Socialism and Capitalism.
(OR)
What are the differences between captalism and socialism?
Answer:

Capitalism	Socialism
1. Capitalism is based on private ownership of means of production.	1. Undersocialism the means of production are under the control of the government.
2. Supply and demand forces determine the prices.	2. There will be centralized planning mechanism.
3. The objective of production is profit maximisation.	3. The objective of production is welfare of the state and people.
4. Concentration of power or wealth will be in few hands.	4. Socialism opposes concentration of power or wealth.
5. The resources are controlled by the capitalists.	5. Social control of resources is seen here.
6. There is no individual freedom or equality of opportunities.	6. The individual freedom and equality of opportunities are given high priority.
7. Eg : West Europe and North America.	7. Eg : Eastern European countries and China.

Question 4.
How was the idea of equality being similar or differently challenged by women and workers movements?
Answer:

1. Workers demands regarding equality –
   a) Equality of opportunities, status, etc., irrespective of birth status.
   b) Opposed discrimination of any sort.
2. The idea of equality challenged by women –
   a) Equality of opportunities to all public dignities, offices and employments.
   b) They demanded equal access to property.
   c) They demanded equal access to civil rights such as voting …. etc.

Question 5.
Draw a poster to illustrate the ideas of “liberty, equality and justice” with in the context of workers and women. Identify occasions where these idea are being violated.
Answer:

In the following occasions the ideas are violated.

• Still the wages given to women labour are low when compared with men.
• Even domestic violence against women is still not able to be controlled.
• Assaults against women are seen everywhere.
• Certain job opportunities are available only for men.

Question 6.
Locate the countries in the world map in which the protest movements took place.
Answer:
The protest movements took place in the following countries.

1. USA
2. England
3. France
4. Germany
5. Italy
6. India
7. China
8. Russia

Question 7.
Read the last paragraph of page 203 and first paragraph of page 204 and comment on them.

You would have read about the struggles of social reformers in 19th century India to end practices like Sati, killing of girl children at birth, enforced widowhood for life etc. and also to extend modern education to women. The growth of education among women enabled many women to take part in public life and organise other women like themselves. This gave rise to women’s movement in India too. Women participated in the national movement and leaders like Gandhiji specially emphasised the importance of women in the movement. Thousands of women joined the freedom movement and helped to shape the ideas of the nationalists. As a result when India became independent women were given complete legal equality vis a vis men. It also sought to end discriminations against them in property laws etc.

Answer:

• The status of women in India has been subject to many great changes over the past few millenia.
• From equal status with men in ancient times though the low points of the medieval period, to the promotion of equal rights by many reformers, the history of women in India has been eventful.
• In modern India women have held high offices including that of the President, Prime Minister, Speaker, etc.

Question 8.
Do you find any social protest movements around you? Interview with the leaders of that movement and prepare a report and present in your class.
Answer:
Yes I found a social movement in my surrounding Area. That is “Prohibition”.
Students : Good morning Madam
Leader (Lady) : Good morning Children
Students : Madam, why did you start the movement on prohibition?
Leader : Because to protect the human beings.
Students : How did you protect them?
Leader : If we start a movement against the liquor, then the government will stop the production.
Students : Why did the government to stop the production of liquor.
Leader : Liquor it is the harmness to the health of the consumer. And how much the worker earn half ofthe amount they spend on liquor. Not spend for his family.
Students : Is it known to the government or not.
Leader : Yes, it is known by government. But they did not take any steps. That’s why we started movement for the safe of families.
Students : How far this movement is helpful to families?
Leader : Children, 90% of our families in India are poor. They are not able to fulfill they proper basic needs also. But they addict to liquor and spoil their life and health and they did not take care about families and education of their children. Gradually, the families become a poor, due to the movement they stop the use of liquor, and use the money for the welfare ofthe family and live happily.
Students : Very good Madam, how did you raise the movement?
Leader : I create awarness among the family members who affected these and gathered and maintain a group and started the movement.
Students : Did you successful any?
Leader : Yes, due to the movement government ban on “cheap liquor”. That’s why we continue our movements to “complete prohibition.”
Students : Very good Madam, you are doing a great job for society. So, we also participated in this movement.

9th Class Social Studies 16th Lesson Social Protest Movements InText Questions and Answers

Question 1.
In what ways do you think ideas of liberty, equality and fraternity wouid have helped to inspire protest movements? (Text Book Page No. 198)

• Industrialization deeply affected the working class.
• Human values were lost.
• There was less scope for dignity and security of life.
• Workers started protesting against their conditions.
• The spread of new political ideas of “liberty”, “equality” and “fraternity” pioneered by the French Revolution gave boost to the protest movements.
• The workers inspired by these ideas demanded
  a) “Liberty” from the bonds of capitalists.
  b) “Equality” of opportunities irrespective of social status.
  c) “Fraternity” inspired them to fight for their dignity.

Question 2.
The government passed a law which provided capital punishment to those who broke machines. Do you think this was justified? (Text Book Page No. 199)
Answer:
No. Giving capital punishment for these who broke machines was not justifiable.

Question 3.
In what way did Marx’s Socialism disagree with Luddism? (Text Book Page No. 202)
Answer:

• Luddism is social protest movement.
• It demanded minimum wages, control over the labour of women and children.
• Demanded work for those who lost jobs because of coming of machines.
• It also demanded right to form trade unions.

Socialism as profounded by Karl Marx

• He wanted production to be an all-society affair rather than a matter of one family.
• He gave importance to collective interest.
• He forced workers not only to fight for better wages but for ending the capital system itself.
• He argued that workers should organize themselves and throughout the capitalists.

Question 4.
Why did Marx consider factory production as superior and desirable? (Text Book Page No. 202)
Answer:

• Marx believed that industrial production is progressive because it has made possible the industrial transformation of the world.
• Marx believed that industrial production made it possible for people to live and earn their livelihood.
• Factory production enabled us to work on small scale too.

Question 5.
What was the main difference between Marx and the earlier socialists? (Text Book Page No. 202)
Answer:
Marx asserts that revolution, which is a political action, is the only way to achieve socialism.

But according to early socialist, reforms and peaceful means are the best way to achieve socialism.

That was the main difference.

Question 6.
Do you think people have achieved ideas of “liberty, equality and fraternity” in the 21st century? (Text Book Page No. 198)
Answer:

• Modern states are welfare states.
• They always provide their people with the ideas of liberty.
• These ideas are included in the constitution itself.
• Now the people have
  a) Liberty of thought and expression.
  b) Equality irrespective of caste, sex, religion and race.
  c) “Fraternity” which protects their dignity.

Question 7.
In India too such laws which protected our farmers from competition from import of cheap agricultural products are being ended. Do you think such imports will benefit the poor people in India? (Text Book Page No. 198)
Answer:
No. I do not think so. Such imports will not benefit poor people in Inaienjecauseney may cause damage to our production also.

Question 8.
Why do you think workers would have supported the ending of the ComLawsandwhy do you think the landowners supported them? (Text Book Page No. 198)
Answer:
The artificially high corn prices encouraged by the Corn Laws meant tnatuiewomng class had to spend the bulk of their income on corn just to survive. Since they had no income. Left over for other purchases, they could not afford manufactured goods. Thus the economical spiral worsened for everyone involved. So the workers would have supported the ending of the Corn Laws.

The beneficiaries of the Corn Laws were the nobility and the other large land holders. Landowners had vested interest in seeing the Corn Laws remain in force. The voting members of parliament had no interest in repeating the Corn Laws. So the landowners supported them.

Question 9.
To what extent do you think breaking the machines helped the workers? (Text Book Page No. 199)
Answer:

• The breakingof machines did not give any direct and immediate benefit to the workers.
• Rather they were given punishments like death sentence or life imprisonment.
• Of course it had long term benefit like their right against exploitation, right to express their views and right to job security were recognized.

Question 10.
Do you see any social movements which are still inspired by these idea round you? (Text Book Page No. 198)
Answer:
A) Yes, so many social movements are inspired by the ideas of “liberty, equality and fraternity”. Some of them are-

1. Social movement of protection of tribals rights is based on the principles of equality.
2. “SC”s demands of equality of opportunity is one of the social movements.
3. “Assault” against “women” in Delhi has led to a mass social movement. That has resulted in the enactment of ‘Nirbhay Act”.
4. “Prohibition of children in factories or any other work” is also based on these ideas.

Question 11.
When new machines are brought in a factory, some workers are usually rendered jobless. Why do you think this happens ? Can there be ways of improving technology without creating unemployment for workers? (Text Book Page No. 199)
Answer:

• A machine can perform the work of 100 workers in lesser time.
• Hence when new machines are brought in a factory, some workers usually rendered jobless.
• When new technology is introduced new jobs are created.
• Therefore, workers should be given propertrainingin “technical know how” to get new job opportunities.

 

SCERT AP Board 9th Class Social Solutions 22nd Lesson Women Protection Acts Textbook Questions and Answers.

AP State Syllabus 9th Class Social Studies Solutions 22nd Women Protection Acts

9th Class Social Studies 22nd Lesson Women Protection Acts Textbook Questions and Answers

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Question 1.
What are the disadvantages of child marriage?
Answer:
Disadvantages of child marriage :

• Underage pregnancy.
• Provision for trafficking and sale of girls.
• Pushing the unmatured into family system.
• Increased abortions, premature births which results not only infant mortality but also the death of mothers.
• Handicapped child births or dead child births.
• Mental as well as physical health problems.
• Obstacle to education.
• Hurdle for physical growth (especially regarding female).
• Become child labourers for family maintenance.

Question 2.
Why has domestic violence become a common practice? In what forms domestic violence is seen? Find out the reasons.
Answer:
Reasons for the domestic violence which became common practice :

1. The family system in the society is on the edge of a blade.
2. No moral values are taught to the children.
3. Lack of understanding capacity in the people.
4. Changing cultures in the society.
5. Hurting manner.
6. Lack of adjustment between family members.
7. Lack of respect towards women.
8. Uncontrolled anger, i.e. mental imbalance.

Question 3.
You have read about various problems girls and women. Have you noticed any sort of problems in your village/town? Specify them and what is to be done.
Answer:
I observe the following in our area.

1. An estimated 85 to 90 percent of domestic violence victims are females.
2. Females are victims of intimate partner violence at a rate about five times that of males.
3. Females between the ages of 16 and 24 are most vulnerable to domestic violence.

To control this domestic violence –

1. Proper counselling should be given to them.
2. Value oriented education should be taught to the children.
3. The nature of thinking from others’ point of view’ should be developed from childhood.

Question 4.
Many acts are made by the government. What do you suggest for better implementation?
Answer:
The Acts cause changes physically. But there should be a change in the minds of the people. The government should take necessary steps for this change.

Question 5.
Write an essay on general problems, the women facing.
Answer:
A Thomson Reuters Foundation expert poll last year ranked India as the world’s fourth most dangerous country for a woman, behind only Afganisthan, Congo, and Pakisthan.

Even though the practice is outlawed 300,000 to 600,000 female foetuses are aborted every year in India because of the preference for boys.

From the time they are born or not born and continuing till late in life when they become wives or mothers, it’s a vicious cycle of discrimination and violence keeps on continuing.

Nearly half of Indian girls are married off before the age of 18. Girls are also seen as a financial liability. The practice of dowry is banned by the government, but it’s still as common as ever.

A 2012 of UNICEF study found more than half of Indian males think it is justifiable to beat a wife under certain circumstances.

Outside the household, crimes against women in India are also on the rise, and the evidence is shocking. According to government data, more than 24,000 cases of rape were reported in 2011.

Indian women in some ways, have also made some strides. Literacy rates have gone up, maternal mortality rates have gone down, and millions of women have joined the workforce.

Authorities acknowledge that action is needed and say they are taking steps to try to better protect women.

Helplines have been set up. A number of fast track courts have also been established because of the December 16 gang rape, exclusively for cases of sexual assault and rape. But women’s rights activists say that when discrimination begins even before birth, change will not come easily.

Question 6.
Imagine that you are Tehsildar. How would you prevent child marriages?
Answer:
As a Tehsildar –

1. I will raise the awareness in parents and their relatives.
2. If they don’t listen to me, I will request the police department to take them into custody. Thus I will prevent child marriages.

Question 7.
Prepare a pamphlet to understand the problems faced by the women.
Answer:

Women in India

Women in Independent India are comparitively in a respectable position. Some of the problems which had been haunting the community of women for centuries are not found now.
But still, for a woman, her life is a battle for survival and dignity from her birth to death. Female infanticide, eve-teasing, sexual exploitation, sexual harassment, rapes are still common. There are still many areas where women have not equal rights and are not encouraged to take up education. Dowry practice is still rampant, eventhough it termed illegal. Women still have to make a lot of sacrifices in every areas of their lives.

Question 8.
Read the paragraph under the title ‘Sexual Assault and Torturing’ of page 275 and comment on it.

Sexual Asssault an Torturing :
Recently, central government has appointed Justice J.S. Verma Committee asking suggestions to prevent sexual assault and abuse. Based on the suggestions, Hon. President of India issued an ordinance on 2nd February, 2013. Some important features of the ordinance, are;

• Minimum 20 years of imprisonment.
• Recruitment of women police to address the complaints from the victims.
• It is not necessary for the victim to attend before the police officers individually.
• There will be no punishment if the accused dies in struggle at the time of attack with acid on women.
• There is scope to short video at the time of complaining and trial on the request of the victims.

Answer:

1. Only legislation and law enforcement agencies cannot prevent the incident of crime against women.
2. There is a need of social awakening and change in the attitude of masses, so that due respect and equal status is given to women.

Question 9.
What facilities does the government provide to the poor for seeking judicial justice?
Consult a lawyer and get the information.
Answer:

• Lok Adalat is a relatively recent product in the justice for the poor.
• Next to that there are Legal Aid Committees, Legal Services Authority.

Services offered by the legal services authority :

1. Payment of court and other process fee,
2. Changes for preparing, drafting and filing of any legal proceedings.
3. Changes of a legal practitioner or legal advisor.
4. Costs of obtaining decrees, judgements, orders or any other documents in a legal proceeding.
5. Costs of paper work, including printing, translation, etc.

These are the facilities provided by the government to the poor for seeking judicial justice.

9th Class Social Studies 22nd Lesson Women Protection Acts InText Questions and Answers

Question 1.
Have you ever seen child marriages? (Text Book Page No. 269)
Answer:
No, I have never seen child marriages.

Question 2.
Have you ever observed harassment and violence made to women and girls? (Text Book Page No. 269)
Answer:
Yes, I have observed in many of my neighbouring houses.

Question 3.
Have you ever observed the various types of domestic violence threatening women in day to day life? (Text Book Page No. 269)
Answer:
I have observed the following,

1. Persisting denial of food,
2. Insisting on perverse sexual conduct
3. Constantly locking a woman out of the house.
4. Denying the woman access to children, thereby causing mental torture.
5. Physical violence.
6. Taunting, demoralising and putting down the woman with the intention of causing mental torture.
7. Abusing children in their mother’s presence with the intention of causing her mental torture.
8. Mental abuse (threaten to harm, stopping from jobs, force to marry whom she doesn’t like).
9. Threatening divorce unless dowry is given.

Question 4.
What shall we do to stop such violence caused to girls and women? (Text Book Page No. 269)
Answer:
We should take the following steps to stop such violence to girls and women.

1. Value oriented education should be given to the children in schools.
2. The persons, who caused violence, should be punished.

Question 5.
Have you ever seen or heard about women being tortured for dowry in your locality? How are they being tortured? What sort of suggestions do you make to prevent? Who will held responsible? (Text Book Page No. 273)
Answer:
Yes, I have seen such a case. My neighbour ‘Vasu’ is harassing his wife for dowry. He has his mothers support also. They usually beat her, abuse her. I suggest her to proceed women protection cell authorities. Then the project officer will hold responsible.

Question 6.
Domestic violence takes place now and then and gradually it becomes a bad habit pattern. More violence generates from violence. How do we stop this? Who will help? (Text Book Page No. 274)
Answer:
In order to put a stop to the domestic violence, there are various things which should be followed.
1) Awareness:
To make the people aware about the drawbacks and harms of the domestic violence, setthe rules againstthe practice and impose stringent punishments to the attacker.

2) Need for stringent laws:
It is very important that the law against domestic violence has to be imposed stringently.

3) Empowered non-government organizations:
Individuals can also seek the help of NGOs.

4) Seek police help:
In case of severe violence, individuals can seek legal help from the police and put an end to domestic violence.

5) Be aware of the domestic violence facts:
The facts of the domestic violence should be learnt by all.

6) Encourage and not threaten:
It is very important to organize a meeting and encourage people to come up with the solutions.

7) Counselling :
It is very important to have counselling in terms of danger.

Question 7.
Sometimes child marriages are performed for the under aged i.e., less than 15 years without their consent. How do we stop such marriages? Who will help us? (Text Book Page No. 271)
Answer:
We can approach the higher officials in the area – to stop the child marriages.

1. District Collector at district level.
2. R.D.O at division level
3. Tehsildar or Mandal level ICDS officer.
4. Gram Panchayat Secretary at village level are the incharges in stopping the child marriages. They will help us.

 

SCERT AP Board 9th Class Social Solutions 3rd Lesson Hydrosphere Textbook Questions and Answers.

AP State Syllabus 9th Class Social Studies Solutions 3rd Lesson Hydrosphere

9th Class Social Studies 3rd Lesson Hydrosphere Textbook Questions and Answers

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Question 1.
Find the odd one out and give an explanation for your choice.
i) a) evaporation
b) condensation
c) salination
d) precipitation
Answer:
Odd one – (c)
Except salination, remaining all belong to the water cycle.

ii) a) tectonics
b) centrifugal force
c) solar energy
d) precipitation
Answer:
a) Tectonics is odd one : Remaining all are the factors that cause ocean currents.

Question 2.
Correct the false statements.
a) Oceans trenches can be located near the continents.
b) Relief features of the oceans are like plains.
c) Most salt in the seas is washed into it from the land over centuries.
d) Temperature of ocean water remains the same across the globe.
Answer:
a) Ocean trenches are the deepest parts of the ocean floor.
b) Relief features of the oceans are Trenches, Deep sea plains and Ridges.
c) True.
d) Temperature of ocean water varies from place to place across the globe.

Question 3.
Describe any one impact of ocean currents for the region you live.
Answer:
The Indian Monsoon current refers to the seasonally varying ocean current regime found in the tropical regions of the northern Indian ocean. The seasonally reversing open ocean currents that pass through south of India are referred to as the winter monsoon current and the summer monsoon current, alternately the north-east monsoon current and the southwest monsoon current.

India receives rainfall due to these currents.

Question 4.
Do you think that the description of blue planet is accurate? Describe any one way in which your activity impacts its oceans.
Answer:
Yes, I do think that the description of blue planet is accurate.

Humans are a part of the natural environment. But our activities lead to degradation of environment.

Oceans are suffering from our activities too, our land practices cause agricultural runoff, sewage, and litter to end up in the oceans daily. Today oceans have also fallen victim to our exploitation. Many large fishes like whales have been disappearing. Damage to oceans is damage to our livelihoods, well-being and nourishment.

Question 5.
Why differences are there in the salinity of oceans?
Answer:

• Salinity of ocean water depends upon many causes, but the main cause is continuous movement of ocean. Water from one place to other due to rotation of earth and winds which takes water here and there causing change in salinity of ocean water (ocean currents and thermohaline currents)
• Melting of ice causes an influx of fresh water, which dilutes ocean water.
• inflow of river water causes an influx of fresh water, which dilutes ocean water.
• Evaporation is only fresh water, which removes fresh water flow an area, causing salt to become more concentrated.
• Rain and snowfall opposite of evaporation, we are adding fresh water and diluting it.
• Wave and wind – various local mixing causes smaller – scale variation in surface salinity.

Question 6.
How is human life dependent upon oceans?
(OR)
How is human life depends on Oceans?
(OR)
How are oceans influencing human life?
Answer:

• Oceans stabilize climates over land.
• They are the storehouses of many chemicals, each of which are useful to humans.
• They disperse many plant & animal species from one continent to another, making biota available in various places. Many of these plants & animals are used as food, neutraceutically as medicines.
• Some people constantly live on boat, due to paucity of land in such areas.
• They are a source of various types of poly-metallic nodules.
• They are used for landing of certain debris of satellites & safely pad most of the meteors that come from outer space, as oceans cover more than 75% of earth’s surface.

Question 7.
Observe the map 1 on page 35 and write down the names of a few warm and cold currents.
Answer:
Some warm and cold currents :

1. Equatorial current (warm)
2. Gulf stream (warm)
3. Labrador current (cool)
4. Greenland current (cool)
5. North Pacific current (warm)
6. West wind drift (cool)
7. East wind drift (cool)
8. Bengula current (warm/cool)

Question 8.
Read the para ‘Ocean as a Resource’ on page 33 and comment on it.
Ocean as a ResourceMost life on earth is under the water. Human beings still have not finished identifying all the different forms of life in the oceans. Human beings have depended on oceans for their food and livelihood from the ancient times. Oceans provided abundant food resources like fish and salt. We also use the sand, gravel, etc. for our industries or housing. Humans extract minerals like chlorine, fluroine, iodine from it. Ocean waves are used for generating power. Ocean floor is mined for oils. Oceans also provide us with gems and pearls. For centuries, we have created our civilisations on its shores and traded across with each other travelling on them.
Answer:
The ocean is one of earth’s most valuable natural resources. It provides food in the form of fish and shell fish. It is used for transportation – both travelling and shipping. It provides a treasured source of recreation for humans. It is mined for minerals and drilled for crude oil.

Question 9.
Prepare a flow chart which shows different land forms.
Answer:

Question 10.
Prepare a list of currents which are found in the Pacific, Atlantic and Indian oceans. Identify the cold and warm currents in different oceans.
Answer:

9th Class Social Studies 3rd Lesson Hydrosphere InText Questions and Answers

Question 1.
Give the reasons for the Sow salinity of Baltic sea. (Text Book Page No. 32)
Answer:

1. Baltic sea is a brackish mediterranean sea located between Central and Northern Europe.
2. The Baltic sea’s salinity is much lower than that of ocean water.
3. Baltic is a small sea on a global scale.
4. The causes for the low salinity of the Baltic sea are
   a) The abundant fresh water run off from the surrounding land.
   b) The shallowness of the sea.
   c) The flow of fresh water into the sea from approximately two hundred rivers and the introduction of salt from the south builds up a gradient of salinity in the Baltic sea.
   d) The Baltic sea is only connected to the world’s oceans by the narrow and shallow waters of the Sound and Belt-sea.
   e) This limits the exchange of water with the North sea and means that the same water remains in the Baltic for a lot of years.

For all the above reasons the salinity of the Baltic sea is less than that of the salinity of the oceans.

SCERT AP Board 9th Class Social Solutions 21st Lesson Human Rights and Fundamental Rights Textbook Questions and Answers.

AP State Syllabus 9th Class Social Studies Solutions 21st Human Rights and Fundamental Rights

9th Class Social Studies 21st Lesson Human Rights and Fundamental Rights Textbook Questions and Answers

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Question 1.
Which of the following is not an instance of an exercise of a fundamental right
a) Workers from Bihar go to Punjab to work on the farms
b) Religious minority set up a chain of schools
c) Men and women government employees get the same salary
d) Parents’ property is inherited by their children
Answer:
d) Parents’ property is inherited by their children

Question 2.
Which of the following freedoms is not available to an Indian citizen?
a) Freedom to criticise the government
b) Freedom to participate in armed revolution
c) Freedom to start a movement to change the government
d) Freedom to oppose the central values of the Constitution
Answer:
b) Freedom to participate in armed revolution

Question 3.
Which of these statements about the relationship between democracy and rights is more valid? Give reasons for your preference.
a) Every country that is a democracy gives rights to its citizens.
b) Every country that gives rights to its citizens is a democracy.
c) Giving rights is good, but it is not necessary for a democracy.
Answer:
I prefer the first sentence. The reasons are –
a)

1. All democratic countries ensure certain rights to its citizens.
2. Rights are reasonable claims of the people.
3. Democratic governments strive to preserve equal ground for all.

b)

1. During the early days of modern history, all despotic governments granted certain rights to the people. That was done under great pressure.
2. Therefore every country that gives rights to its citizens is not a democratic.

c) The rights are so important that they are also expressed by many democratic countries and codified by the UNO and find first place in the universal declaration of human rights. Hence it is necessary for democracy to give rights.

Question 4.
Are these restrictions on the right to freedom justified? Give reasons for your answer.
a) Indian citizens need permission to visit some border areas of the country for reasons of security.
b) Outsiders are not allowed to buy property in some areas to protect the interest of the local population.
c) The government bans the publication of a book that can go against the ruling party in the next elections.
Answer:
a)

1. Yes, it is justifiable.
2. It is the responsibility of the government to protect the life of the people.
3. Border areas are high risk areas and tension always persists there.
4. Hence permission is necessary.

b)

1. No, not justifiable.
2. People in democracy have freedom to reside in any part of India.
3. Hence, this statement is against the fundamental rules.
4. But, there is one clause in our Constitution itself, that we cannot buy property in the state of Jammu and Kashmir.
5. So Jammu and Kashmir is an exemption to the fundamental rule.

c)

1. No, not justifiable.
2. Democracies grant civil liberties to its citizens.
3. Under civil liberties, we can express our ideas through media or books.
4. But generally, government bans certain books in order to avoid internal tensions.

Question 5.
Look through this chapter and the previous one and make a list of the six Fundamental Rights in the Constitution.
(OR)
What are fundamental rights? How are these helping us to live better?
(R)
Write any four fundamental rights enjoyed by the citizens of India.
Answer:
There are six fundamental rights. They are :

1. Right to equality
2. Right to freedom
3. Right to religious freedom
4. Right against exploitation
5. Right to education and culture
6. Right to constitutional remedies.

Fundamental rights protect the liberties and freedom of the citizens against any invasion by the state, prevent the establishment of the authoritarian and dictatorial rule in the country. They are very essential for the all-round development of the individuals and the country.

Question 6.
Are the Fundamental Rights being violated in each of the following cases? If so, which Fundamental Right or Rights? Discuss with your classmates.
a) Suppose a person is kept in a police station for 4 days without being told the reasons, which law was broken?
b) Suppose your neighbor tries to claim some of your land as her own.
c) Suppose your parents do not allow you to go to school. They make you take up a job in a match factory instead because they cannot afford to feed you properly.
d) Suppose your brother refuses to give you the land that you have inherited from your father.
Answer:
a)

1. In the first case, arresting a person without proper reason and keeping in a police station for 4 days is against the fundamental rights.
2. “Rights to life” and personal liberty ensures that “no one can be arrested without being told the grounds for his arrest.
3. “Hebeaus Corpus” writ protects the individuals from the arrest.

b)

1. Occupation of one’s land by another is not a violation of fundamental rights.
2. Right to property is a legal right.

c)

1. Not allowing a child to go to school is definitely violation of fundamental right.
2. “Right to education” is a part of “right to life”.
3. Government is responsible for providing free and compulsory education to all the children up to the age of 6 to 14 years.

d)

1. Refusal on part of your brother to give you land that you inherited is not violation of fundamental rights.
2. Right to property is a legal right and civil courts will solve the problem.

Question 7.
Suppose you are an advocate. How would you argue the case for a group of people who come to you with the following request:
“The river in our area is getting very polluted by the factories upstream. We get our drinking water from the river. People in our villages keep falling ill because of the polluted water. We have complained to the government but there has been no action from their side. This is surely a violation of our Fundamental Rights.” ;
Answer:

• Being an advocate I would like to file a writ in the court for the interests of the public.
• This is surely a violation of our fundamental rights.
• Hence I argue the case in such a way that immediately stay order would be issued to close down the factory.
• When the government did not respond to our complaints, courts would definitely safeguard our interests.

Question 8.
Read the paragraph under the heading ‘Abolition of Title’ and answer the following question:
Abolition of Title:
In another move to remove arbitrary and unequal classification of the aristocratic class and the bourgeoise, the Constitution prohibits the State from conferring any titles. The British government had created an aristocratic class known as Rao Bahadurs and Khan Bahadurs in India -these titles were also abolished. Citizens of India cannot accept titles from a foreign State. However, military and academic distinctions can be conferred on the citizens of India. The awards like the Bharat Ratna, the Paramveer Chakra, and the Padma Vibhushan cannot be used by the recipient as a title and do not, accordingly, come within the constitutional prohibition.
The awards can’t be used by the recipient as a title. Why?
Answer:

• In order to remove arbitrary and unequal classification of the aristocracy and middle class, the constitution prohibits the state from conferring any titles.
• Hence the awards like the Bharat Ratna, the Padma Vibhushan cannot be used by the recipients as a title.

Question 9.
Analyse an incident you know about where the Fundamental Rights are violated.
Answer:

• The 1984 Anti-Sikh Riots was a four-day period during which sikhs were massacred by members of the secular-centrist Congress party of India, some estimates that more than 2000 were killed. (Religious violation)
• Dalits and indigeneous peoples continue to face discrimination, exclusion and acts of communal violence.
• Narco analysis test (against to the Indian constitution), “nobody may be made a witness against himself, etc.

Question 10.
Invite a senior advocate into your classroom and collect the following information by conducting an interview.
– violation of fundamental rights and its consequences
– violation of children rights
– ways of struggle for rights in democracy
– any other related
Answer:
Students : Good morning sir.
Advocate : Good morning children.
Students : Sir, today we are going to known about the fundamental rights and importance of other rights from you sir.
Advocate : Yes, children, I will explain. What do you know about.
Students : Sir what will happen, if we violate fundamental rights.
Advocate : Courts will punish us.
Students : Sir please explain one example?
Advocate : If any person is created a nusence in the public places, he created inconvience to the freedom of other people. Then the police arrested that person and kept in the prision.
Students : What will happen when violate the children’s rights?
Advocate : Children are the tomorrow’s citizens generally 6-14 years age is considred as children. So that age children should be in school. But if they did not go to school and work in any where the owner will punish by government / court. Parents should provide education to their children. That is their fundamental right.
Students : Sir what are the ways to struggle for rights in democracy?
Advocate : Students in a democracy always we are fighting for our rights. We will achieve our rights in a peaceful manner. So movements will be in a democratic manner not in a violent manner. These are in through petitions, strikes etc.
Students : Sir please explain any other related issues.
Advocate : Children fundamental rights are provided by our constitution. We will enjoy that not violate and not create any inconvienient to others it will we create any we will punish by government and lost our valuable future also.
Students : Thank you sir.
Advocate : Ok children. Bye.

9th Class Social Studies 21st Lesson Human Rights and Fundamental Rights InText Questions and Answers

Question 1.
Write a few important features of Preamble you studied last year. (Text Book Page No. 256)
Answer:
The Preamble is the heart and soul of our constitution. The important features are –

1. The Preamble starts with the words “We the people of India”. This ensures that sovereignty vests with the people.
2. It also confirms or ensures justice, equality, liberty, and fraternity to all its citizens.
3. It declares our country as sovereign, socialistic, secular, democratic, republic. Each of the words have different meaning.

Question 2.
What kinds of rights to equality does the Constitution ensure? Give examples. (Text Book Page No. 259)
Answer:
The Constitution ensures the following rights to equality to its citizens.

1. Equal protection of law * The laws apply to all in the same manner, regardless of a person’s income, status, background, etc.
2. Social Equality – The state condemns any sort of discriminations of human beings.
3. Equality of opportunity – The constitution guarantees equality of opportunity for all citizens regarding education or employment.
4. Abolition of untouchability.
5. Abolition of titles – In order to remove inequalities “Titles” of any sort are abolished.

Question 3.
What would happen if the Fundamental Right to Equality was not in the Constitution? Discuss. (Text Book Page No. 259)
Answer:

1. Democratic systems preserve equal grounds for all.
2. Democracies work on the principle of equality which is also known as “rule of law”.
3. If the fundamental “Right to equality” was not in the Constitution, the very essence of democracy would be lost.

Question 4.
What associations are there in your area? (Text Book Page No. 261)
Answer:
There are so many associations in my area. Some of them are –

1. Teachers Associations
2. Workers Association
3. Foremen’s Association
4. Students’ Associations
5. Auto – Rickshaw Association
6. Trade Union Associations
7. Rice Millers’ Associations
8. Fishermen’s Associations, etc.

Question 5.
Why are workers’ unions formed? What problems do they face? (Text Book Page No. 261)
Answer:
Workers unions are formed to protect the rights of workers and to solve their problems. These unions hold meetings to discuss their problems and take their demands to the officers of the factory. The following are their problems.
a) Their working conditions will not be healthy.
b) Salaries, dearness allowances, pensions, etc., will not be paid to them in time.
c) Sometimes their services will not be regularised.
d) They will not provide any educational facilities to their children of the factory workers.
e) Medical reimbursement, generally, not given to them.

Question 6.
Why do people want to move and settle in various parts of the country? (Text Book Page No. 261)
Answer:
In search of job opportunities people move and settle in various parts of the country.

Question 7.
What do you remember about the difference between the role of the police and that of the court? (Text Book Page No. 262)
Answer:

• Police generally file a case on any person who had committed a crime.
• He has to submit the accused in the case before the court.
• The court decides whether a person is guilty or not. And finally gives judgement.

Question 8.
What are the different types of schools you see in your area? Why do you think are there such different types of schools? (Text Book Page No. 262)
Answer:
There are the following types of schools
Basing on the management –

1. Zilla Parishad School
2. Mandal Parishad Schools
3. Government Schools
4. Social Welfare Schools
5. Tribal Welfare Schools
6. Government aided schools
7. Private Schools

Basing on the classes –

1. Primary Schools (I class to 5th class)
2. Upper Primary Schools (1st class to 7th class)
3. High Schools (6th class to 10th class)

The children, whose parents are rich and can afford private school, go to private schools. And rest of the children generally go to government schools.

Question 9.
Can anyone not follow any religion if he/she wishes? (Text Book Page No. 263)
Answer:
No, everyone can follow whatever religion they want. “Right to religious freedom” is our fundamental right.

Question 10.
State some instances of violations of Human Rights. (Text Book Page No. 266)
Answer:

1. Arbitrary arrests
2. Denial of right to information and corruption
3. Sexual cruelty
4. Rape of women
5. Delay in investigation of crimes
6. Female infanticide
7. Kidnapping for ransom
8. Deplorable conditions of women, children and downtrodden people
9. Discrimination against women in the family
10. Cruelty to domestic servants

The above are some instances of the violations of human rights. These violations continue unchecked because people are not aware of their human rights.

Question 11.
Read the passage and answer the following questions. (Text Book Page No. 262)
The Constitution states, “no child below the age of 14 shall be employed to work in any factory or mines or engaged in any other hazardous employment.” Accordingly, laws have been made that prohibit children from making matches, crackers, beedis, and carpets, or doing printing and dyeing, etc.
Do you think this right has been made available to children in the villages and cities in your area?
Answer:
There are number of children who are still working in small scale industries like dyeing, printing, beedi making etc.

Question 12.
Discuss whether you think each of the following is a violation of the Fundamental Right to Equality, Also discuss whether you think it is constitutionally right or wrong to do such things. (Text Book Page No. 259)

• While filling water from a public source, some people object if the vessel of another person touches their pots.
• Some communities are never provided a place to live within the village but always outside.
• In some schools, certain children are not allowed to serve water because they belong to a particular caste.
• Members of some communities do not go to many places of worship because they fear that they will be ill treated or beaten up.

Answer:

• The above examples are the clear evidences of practice of untouchability.
• The practice of untouchability is a crime.
• Anyone doing so is punishable under law.

Question 13.
With the help ofthe teacher find out the minimum wages in your state. (Text Book Page No. 262)
Answer:
Minimum wages were received by the people in different sector in our state.
Male – Rs. 200 (per day) – Female – Rs. 150 (per day)
Teacher – Rs. 300 to 2000 (per day).

Agriculture labour
Male – Rs. 180 (per day)
Female – Rs. 120 (per day)

Mason
Male – Rs. 300 (per day)
Female – Rs. 180 (per day)

Question 14.
How does the practice of “Sati” violate fundamental rights? (Text Book Page No. 263)
Answer:

• No citizen can be denied his life and liberty except by law.
• “The right to life” does not include “the right to die”, and hence suicide, forced death or sati, etc. are offences.
• “Sati”, hence, is violation of fundamental right of “the right to live”.

Question 15.
What is the responsibility of the government towards workers who are able to find some work, in the city but don’t have a proper place to live? (Text Book Page No. 261)
Answer:

• Our Government has introduced subsidised housing schemes to the people of below poverty line.
• Under urban basic schemes, Indira Aavas Yojana, Rajiv Gruha Yojana, etc., so many people acquired houses.
• They are constructed in the prime localities of the cities.
• Most of the slums in the cities were removed.
• Development is still going on in this regard.

Question 16.
Write a petition to the NHRC if you know any instances of human rights violation in your area. (Text Book Page No. 266)
Answer:

Question 17.
Is there a State Human Rights Commission in our state? Find out about its activities. (Text Book Page No. 266)
Answer:
Yes, there is a State Human Rights Commission in our state.
A Human Rights Commission, also known as a Human Relations Commission is a body set up to investigate, promote or protect human rights.

Its activities are

1. Inquire into any violation of human rights.
2. Look into negligence in the prevention of human rights violation by a public servant.
3. They can take cognizance either sumotu or on a petition presented to it or on an order of a court.
4. They intervene in any proceeding involving allegation of violation of human rights pending before a court etc.

 

AP State Syllabus AP Board 9th Class Physical Science Important Questions Chapter 1 Motion.

AP State Syllabus 9th Class Physical Science Important Questions 1st Lesson Motion

9th Class Physical Science 1st Lesson Motion 1 Mark Important Questions and Answers

Question 1.

From the above data, what can you say about the motion of the object?
Answer:
The object is in the uniform motion and its speed is constant.

Question 2.
Frame any one question to understand Newton’s third law of motion.
Answer:
How does rocket engine work?

9th Class Physical Science 1st Lesson Motion 2 Marks Important Questions and Answers

Question 1.
Distinguish between speed and velocity. jawjMB
Answer:

Question 2.
What happens to the speed and the direction of motion of a ball rolling down an inclined plane?
Answer:

1. Speed of the rolling ball changes.
2. But the direction of motion remains constant.

Question 3.
A motor cyclist drive from A to B with uniform speed of 30 km/hour and returns back with a speed of 20 km/hour. Find the average speed.
Answer:
Speed of the motor cyclist from A to B = 30 km/hr.
Speed of the motor cyclist from B to A = 20 km/hr.

Question 4.
A train of length 100 m. is moving with a constant speed of 10 m/s. Calculate the- time taken by the train to cross the electric pole.
Answer:
Length of the train = 100 m; Speed of the train = 10 m/s
Time taken to cross the elctrical pole (t) = s/v = \(\frac{100}{10}\) =10 sec.
[∵ Distance travelled while crossing an electrical pole = Length of the train]

Question 5.
Calculate the average speed of “Ussahi Bolt” who sprints 100m in 9.81 sec. during 2016 Rio Olympics to win Gold medal.
Answer:
Distance covered by Ussain Bolt = 100 m
time = 9.81s.

Question 6.
Explain the terms in the formula v = u + at.
Answer:
v = u + at
u = initial velocity
v = final velocity
a = acceleration
t = time

9th Class Physical Science 1st Lesson Motion Important Questions and Answers

9th Class Physical Science 1st Lesson Motion 1 Mark Important Questions and Answers

Question 1.
Define uniform acceleration.
Answer:
Acceleration is uniform when in equal intervals of time, equal changes in velocity occur.

Question 2.
Write an equation of motion to find the distance travelled when initial velocity, time, and acceleration are given.
Answer:
s = ut + \(\frac{1}{2}\) at²

Question 3.
Draw a displacement vector from Visakhapatnam to Hyderabad to the following diagram.

Answer:

Question 4.
Difine acceleration.
Answer:
The rate of change of velocity in an object is known as its acceleration.

Question 5.
What is the key difference between distance and displacement?
Answer:
Distance is the length of the path traversed by an object in a given time interval and displacement is the shortest distance covered by the object in a specific direction.

Question 6.
The distance travelled by a particle in time’t’ is given by s = (2.5 m/s²) t². Find the average speed of the particle during the time ‘O’ to ‘5’ sec.
Answer:
The distance travelled by the particle from 0 to 5 sec is s = 2.5 m/s² × 5² = 62.5 m

Question 7.
A table clock has its minutes hand 4 cm long. Find the average velocity of the tip of the minute hand between 6.00 AM to 6.30 AM.
Answer:
The minute hand of a clock comes into a straight line from 6.00 AM to 6.30 AM.
Hence the displacement of the minute hand S = 2 x 4 = 8 cm
Time = 30 minutes = 1800 sec.

Question 8.
A ball is thrown up with an initial speed of 4m/sec. Find the maximum height reached by the body.
Answer:

Question 9.
The adjacent distance – time graph indicates
A) A particle travels constantly along X-axis.
B) Particle is at rest.
C) The velocity of the particle increases up to a time t0 and then remains constant.
D) The particle travels up to time t(( with constant velocity and then stops.

Answer:
C

Question 10.
A man used his car. The initial and final odometer readings are 4849 and 5549 respectively. The journey time is 70h. What is average speed of the journey?
Answer:
Distance covered = 5549 – 4849 = 700 km. ; Time = 70 h.

9th Class Physical Science 1st Lesson Motion 2 Marks Important Questions and Answers

Question 1.
An object is moving in a circular path of radius 7 m. What is the distance and displacement of an object after one revolution ?
Answer:
Radius (r) = 7 m
22
Distance covered by object = 2πr = 2 × \(\frac{22}{7}\) × 7 = 44 m
The object come back to original position displacement of the object is 0.

Question 2.
An object reaches other end of a diameter in a circular path of radius 7 m in 7s. Find speed and velocity of the object?
Answer:

Question 3.
A person moves 3 km towards east and turned toward north and travelled a distance of 4 km. Find total distance and total displacement.
Answer:

Question 4.
An object completes 1/4th revolution of a circular path of radius r. Then find the ratio of distance and displacement.
Answer:

Question 5.
a) What is a vector? Give example.
b) What is a scalar? Give example.
Answer:
a) Vector :
The physical quantity which is specified with magnitude and direction is called a vector.
Eg : Displacement, velocity are vectors.

b) Scalar :
The physical quantity which does not require any direction for its specification is called ‘scalar’.
Eg : Distance, time are scalars.

Question 6.
How does a vector represents? Explain.
Answer:

1. A vector can be represented as a directed line segment.
2. It’s length indicates magnitude and arrow indicates it’s direction.
3. Vector is represented by an arrow as shown in the figure.
   
   Here point ‘A’ is called tail and point ‘B’ is called head.

Question 7.
Bhavan did not recognise the difference between 40 meters displacement and distance. Then Anitha ex- plained the difference by asking some questions to Bhavan. What would be those questions?

Note : She used this diagram.
Answer:
By using the diagram Anitha asked the following questions :

1. What is the distance between A and D?
2. Which is the shortest distance from A to D?
3. What is the direction of an object if it travelled in the route A → B → C → D? Can you determine its direction?
4. On which direction the distance is short from A to D? Measure it.
5. Which path has specified direction?
   Either A → B → C → D or A → D?
6. Which path has specified magnitude?
   Either A → B → C → DorA → Dor Both?
7. Which is the shortest, distance among the two paths?
8. If the displacement has both magnitude and specified direction, which path is considered as a displacement?
9. What is the difference between distance and displacement?

Question 8.
What happens to the direction of velocity and acceleration when the
i) speed of an object increases?
ii) speed of an object decreases?
Answer:
i) If the speed of an object increases, the direction of velocity and acceleration are one and the same.
ii) If the speed of an object decreases, the direction of velocity and acceleration are in opposite directions. Here, at a certain instant the speed becomes zero.

Question 9.
Draw a displacement vector and a velocity vector to the given path of motion of a body.

Answer:

Question 10.
Find the acceleration of a bus if its speed increases from 0 m/s to – 600 m/s in 1 minute?
Answer:

The acceleration of the bus is 10 m/sec².

9th Class Physical Science 1st Lesson Motion 4 Marks Important Questions and Answers

Question 1.
Distinguish between distance and displacement.
Answer:

Distance	Displacement
1. Distance is the length of the path travelled by an object in a given time interval.	1. Displacement is the shortest distance covered by the object in a specified direction.
2. SI unit of distance is ‘meter’.	2. SI unit of displacement is ‘meter’.
3. Distance is scalar.	3. Displacement is vector.
4. Distance will not be zero even if it reaches the initial position after its journey.	4. Displacement will become zero, if it reaches its initial position after its journey.

Question 2.
Explain the terms uniform and non-uniform motions.
Answer:
Uniform motion :

1. If a body covers equal distances in equal intervals of time, assuming the direction of motion is constant, then the motion is said to be uniform motion.
2. The motion of a body is said to be uniform when its velocity is constant.
3. The s -1 graph for a uniform motion is a straight line.
4. Ex : Motion of hands in a clock.

Non-uniform motion :

1. If a body covers unequal distances in equal intervals of time, assuming the direction of motion is constant, then the motion is said to be non-uniform motion.
2. A body is said to be in non-uniform motion if its velocity changes with time.
3. The s -1 graph for non-uniform motion is not a straight line.
4. Ex : Motion of a car/bus between two stations on a road.

Question 3.
Derive equations of uniform accelerated motion.
Answer:
1) Let ‘u’ be the velocity at the time t = 0 and V be the velocity at the time’t’ and let ‘s’ be the displacement covered by the body during time’t’ as shown in figure.
2) From the definition of uniform acceleration,

Question 4.
Describe the graphical method to calculate the instantaneous speed at a given point.
Answer:

1. Consider a car moving along a straight road with varying speed.
2. Take time elapsed on X – axis and distance cov¬ered on Y – axis and plot a graph for its motion at regular intervals of time.
3. A general case of motion with varying speed is shown in the figure.
4. The average speed during the time interval from
   
5. Then we calculate average speed for a very short time interval encompassing the time at an instant t3 which is so short interval, that value of average speed would not change materially if it was made even shorter.
6. The instantaneous speed is represented by the slope of the curve at a given instant of time.
7. The slope can be found by drawing a tangent to the curve at that point.
8. The slope of the curve gives speed of the car at that instant.

Question 5.
What is difference between speed and velocity?
Answer:

Question 6.
Derive s = ut + \(\frac{1}{2}\) at²
Derive one equation for displacement of a body which is in the uniform acceleration.
Answer:
1) Let u be the initial velocity,
v be the velocity at time ‘t’.
a be the acceleration,
s be the displacement

Question 7.
A car travelled from A to E station in 3 minutes. Viewing path given below in the figure. find
i) distance
ii) displacement
iii) speed
iv) velocity

Answer:
i) Distance = AB + BC + CD + DE = 540 + 460 + 540 + 260 = 1800 m

ii) Displacement = Distance between A and E

Question 8.
Give an example to each situation in daily life.
i) Speed changes when direction remains constant.
ii) Direction of motion changes when speed remains constant.
iii) Speed and direction simultaneously change.
Answer:
i) The palk taken by a ball which was released from the top of the inclined plane. Here the direction of motion remains constant but velocity gradually increases.

ii) Whirl a stone which is tied to the end of the string continuously.
Here it’s direction of motion changes but speed remains constant.

iii) The path taken by a stone, which was thrown into the air.
Here speed and direction of the motion both changes simultaneously.

AP State Syllabus AP Board 9th Class Physical Science Solutions Chapter 11 Sound Textbook Questions and Answers.

AP State Syllabus 9th Class Physical Science Solutions 11th Lesson Sound

9th Class Physical Science 11th Lesson Sound Textbook Questions and Answers

Improve Your Learning

Pick out the correct answer :

Question 1.
When we say sound travels in a medium (AS 1)
A) the medium travels
B) the particles of the medium travel
C) the source travels
D) the disturbance travels
Answer:
D) the disturbance travels

Question 2.
A sound wave consists of (AS 1)
A) number of compression pulses only
B) number of rarefaction pulses only
C) number of compression and rarefaction pulses one after the other
D) vacuum only
Answer:
C) number of compression and rarefaction pulses one after the other

Question 3.
Hertz stands for oscillations per (AS 1)
A) second
B) minute
C) hour
D) milli second
Answer:
A)second

Question 4.
When we increase the loudness of sound of a TV, the property of sound that changes is (AS 1)
A) amplitude
B) frequency
C) wavelength
D) speed
Answer:
A) amplitude

Question 5.
The characteristic of the sound that describes how the brain interprets the frequency of sound is called (AS 1)
A) pitch
B) loudness
C) quality
D) sound
Answer:
A) pitch

Question 6.
In a stethoscope, sound of heart beats travel through stethoscope tube (AS 1)
A) by bending along the tube
B) in a straight line
C) undergoing multiple reflections
D) all of the above
Answer:
C) undergoing multiple reflections

Question 7.
Explain the following terms : (AS 1)
a) amplitude
b) wavelength
c) frequency
Answer:
a) Amplitude :
The maximum variation in density or pressure from the mean value is called amplitude.
(or)

The maximum disturbance of particles of a medium from their mean position is called amplitude.

b) Wavelength :
The distance between two consecutive compressions or two consecutive rarefactions is called the wavelength of a sound wave, denoted by W. Wavelength is measured in ‘meters’.

c) Frequency :

1. The number of oscillations of the density of the medium at a place per unit time is called the frequency of the sound wave.
2. Frequency is denoted by ‘o’.
3. The S.I. unit of frequency is ‘Hertz’.

Question 8.
Deduce the relation between wavelength, frequency, and speed of sound. (AS 1)
Answer:
1) Speed of sound can be defined as the distance by which a point on the wave, such as a compression or rarefaction, travels in unit time.

2) Let the distance travelled by a wave in T seconds = X metres

3) The distance travelled by a wave in 1 second = \(\frac{\lambda}{\mathrm{T}}\) meters

4) Thus by definition of speed of wave, v = \(\frac{\lambda}{\mathrm{T}}\) ……….. (1)

5) We know that frequency and time period are related as υ = \(\frac{1}{T}\) ……….. (2)

6) From (1) and (2) we get v = λ .υ
∴ Speed of sound = Frequency × Wavelength

Question 9.
How are multiple reflections of sound helpful to doctors and engipeeps? (AS 7)
Answer:
1) Doctors use multiple reflections of sound to hear the sounds produced with in the body using stethoscope.

2) Doctors can see the images of patient’s organs like liver, gall bladder, uterus, etc. to know the abnormalities in their functioning, using ultrasounds.

3) Engineers use the reflections of sound in designing concert halls and cinema halls.

4) Generally the ceilings of concert halls, conference halls, cinema halls are designed such that sound after reflection reaches all corners of the hall as shown in the figure.

Question 10.
Name two quantities that vary periodically at a place in air as a sound wave travels through it. (AS 1)
Answer:
The two quantities that vary periodically at a place in air as a sound wave travels through it are density and pressure of particles.

Question 11.
Which has larger frequency – infrasonic sound or ultrasonic sound? (AS 7, AS 2)
Answer:

• Infrasonics are the sounds of frequency less than 20 Hz.
• Ultrasonics are the sounds of frequency greater than 20 kHz.
• Hence the ultrasonics have larger frequency.

Question 12.
The grandparents and parents of two-year-old girl are playing with her in a room. A sound source produces a 28 kHz sound. Who in the room is most likely to hear the sound? (AS 2, AS 7)
Answer:

• The two-year-old girl is able to hear the sound.
• Children can hear sounds of somewhat higher frequencies up to 30 kHz.

Question 13.
Does the sound follow same laws of reflection as light does? (AS 1)
Answer:

• Reflection of sound follows the same laws as the reflection of light when sound is reflected.
• The directions in which the sound is incident and reflected make equal angles with the normal to the reflecting surface.

Question 14.
Why is soft furnishing avoided in concert halls? (AS 7)
Answer:

• Sound reflects like the reflection of light.
• But unlike to light, sound reflects more on rough surfaces than soft surfaces.
• In concert halls, sound must undergo multiple reflections, so as to reach all corners of the hall.
• Hence for better reflection, soft furnishing is avoided in concert halls.

Question 15.
Two sources A and B vibrate with the same amplitude. They produce sounds of frequencies 1 kHz and 30 kHz respectively. Which of the two waves will have larger power? (AS 1)
Answer:
Frequency of source A = 1 kHz; Frequency of source B = 30 kHz

As the speed of wave increases with frequency and both the waves have same amplitude, the sound produced from source B has larger power.

Question 16.
What do you understand by a sound wave? (AS 1)
Answer:

• Sound is produced from a vibrating body.
• It travels through air in the form of a wave.
• Sound waves are longitudinal.

Question 17.
Define the wavelength of a sound wave. How is it related to the frequency and the wave speed? (AS 1)
Answer:
Wavelength :
The distance between two consecutive compressions or rarefactions is called wavelength.

Relation between wavelength, frequency, and wave speed :

1. Speed of sound can be defined as the distance by which a point on the wave, such as a compression or rarefaction, travels in unit time.
2. Let the distance travelled by a wave in T seconds = λ metres
3. The distance travelled by a wave in 1 second = \(\frac{\lambda}{\mathrm{T}}\) meters
4. Thus by definition of speed of wave, v = \(\frac{\lambda}{\mathrm{T}}\) ………… (1)
5. We know that frequency and time period are related as o = \(\frac{1}{T}\) ……….. (2)

Question 18.
Explain how echoes are used by bats to judge the distance of an obstacle in front of them. (AS 1)
Answer:

• Bats search out prey and fly in dark night by emitting and detecting reflections of ultrasonic waves.
• The high pitched ultrasonic squeaks of the bat are reflected from the obstacles or prey and returned to bat’s ear.
• The nature of reflections tells the bat where the obstacle or prey is and what it is like.
• The bats use ultrasound for navigation and location of the food in dark.

Question 19.
With the help of a diagram describe how compression and rarefaction pulses are produced in air near a source of sound. (AS 5)
Answer:

• Consider a vibrating membrane of a musical instrument like a drum or tabla.
• As it moves back and forth, it produces a sound.
• The figure shows the membrane at different instants and the condition of the air near it at those instants.
• As the membrane moves forward, it pushes the particles of air in the layer in front of it.

• So, the particle of air in the layer get closer to each other, hence the density increases.
• This layer of air pushes and compresses the layer next to it and so on.
• We call this disturbance as compression pulse.
• When the membrane moves backward, it drags back the layer of air near it. Hence the density decreases.
• The particles of air in the next layer on the right move into fill this less dense area.
• This is a rarefaction pulse moves to right.
• As the membrane moves back and forth repeatedly, compression and rarefaction pulses are produced, one after the other.
• These two pulses travel one behind the other, carrying the disturbance with it.

Question 20.
How do echoes in a normal room affect the quality of the sounds that we hear? (AS 7)
Answer:

• Echo is a reflected sound, arriving at the position of listener more than 0.1s after the direct sound.
• Quality is the characteristic of a sound which enables us to distinguish between musical notes emitted by different musical instruments.
• In a normal room, if echo is formed, we can hear multiple sounds, at same time.
• Our ear cannot perceive and judge the sound from where it is coming.
• So, quality of sound does not work here.

Question 21.
Explain the working and applications of SONAR. (AS 1)
Answer:

• SONAR stands for Sonographic Navigation And Ranging.
• This is a method for detecting and finding the distance of objects under water by means of reflected ultrasonic waves.

Working of SONAR:

1. SONAR system consists of a transmitter and a detector in the “Observation Centre” on board of a ship.
2. From the observation centre, ultrasonic waves of high frequency are sent in all directions under the water through transmitter.
3. These waves travel in straight lines till they hit an object such as a submarine, a sunken ship, etc.
4. The waves are then reflected and are received back by the receiver at the observation centre.
5. The study of these reflected waves gives information about the direction of the object located.
6. The time between sending ultrasonic wave and receiving its echo, the distance of the object is calculated.
7. Reflections from various angles can be utilized to determine the shape and size of the object.

Mathematical expression :

1. Let’d’ be the distance between SONAR and an underwater object.
2. ‘t’ be the time between sending an ultrasonic wave and receiving its echo.
3. ‘u’ be the speed of sound in water.
4. The total distance covered by the wave from the SONAR to the object and back is 2d.
5. From the equation s = ut ⇒ 2d = ut ⇒ d = \(\frac{ut}{2}\).

Application:
Marine geologists use this method to determine the depth of the sea and to locate underwater hills and valleys.

Question 22.
Find the time period of a source of a sound wave whose frequency is 400 Hz. (AS 1)
Answer:
Frequency υ = 400 Hz
Time period T =?

Question 23.
A sound wave travels at a speed of 340 m/s. If its wavelength is 2 cm, what is the frequency of the wave? Will it be in the audible range? (AS 1)
Answer:
Speed of sound v = 340 m/s.; Wavelength λ = 2 cm = 0.02 m.
Frequency υ =?

The audible range of sound wave is 20 Hz to 20 kHz.
Hence this is in the audible range.

Question 24.
Given that sound travels in air at 340 m/s, find the wavelength of the waves in air produced by a 20 kHz sound source. If the same source is put in a water tank, what would be the wavelength of the sound waves in water? (AS 7)
Speed of sound in water = 1,480 m/s.
Answer:
In air:
Speed of sound wave (v) = 340 m/s ; Frequency of source of sound (o) = 20 kHz
Wavelength of the sound wave λ =?
v = υλ

∴ Wavelength of the sound wave in air = 17 m

Same source is kept in water :
∴ Speed of sound in water (v) = 1480 m/s
Frequency of sound wave (p) = 20 kHz
Wavelength of sound wave λ =?
v = υλ

∴ Wavelength of the sound wave in water = 74 m

Question 25.
A man is lying on the floor of a large, empty hemispherical hall, in such a way that his head is at the centre of the hall. He shouts “Hello!” and hears the echo of his voice after 0.2 s. What is the radius of the hall ? (Speed of sound in air 340 m/s) (AS 7)
Answer:
Let the distance travelled by the sound wave = 2d m

As the head of the man is at the centre of hemispherical room, then ‘d’ is the radius of the hall.
∴ Radius of the hall = 34 m

Question 26.
“We know that sound is a form of energy. So, the large amount of energy produced due the sound pollution in cosmopolitan cities can be used to our day-to-day needs of energy. It also helps us to protect biodiversity in urban areas”. Do you agree with this statement? Explain.
Answer:

1. Sound is a form of mechanical energy.
2. So, the mechanical energy can be converted into electrical energy.
3. Experiments are going on this concept.
4. If this is successful, we have the following benefits.
   a) Sound pollution can be controlled.
   b) Conventional methods of producing electrical energy from coal or water will cause in loss of biodiversity. This can be avoided.
   c) Natural resources like water can be protected.
   d) Increasing needs of energy can be overcome by this method.

Question 27.
How do you appreciate efforts of a musician to produce melodious sound using a musical instrument by simultaneously controlling frequency and amplitude of the sounds produced by it.
Answer:

• The sounds which produce pleasing effect on the ear are called musical sounds.
• Any instrument which produces musical sound is called musical instrument.
• The person who plays a musical instrument to produce melodious sound is called a musician.
• The musician must have control on breathing, concentration on the output of the sound, which is a very hard task.
• For this the musician needs a lot of practise.
• With the musician’s practise and knowledge over musical notes only we can hear melodious sound otherwise it could only be a noise.
• Hence the efforts of a musician are highly appreciable.

Question 28.
You might have observed that sometimes your pet dog starts barking though no one is seen near in its surroundings or no disturbance heard nearby. Does this observation raise any doubts in your mind about the peculiar behaviour of dog after your understanding about ‘range of hearing the sound’. If yes, write them.
Answer:

• Dogs can hear sounds of frequencies up to about 50 kHz, which is ultrasonic.
• After hearing this ultrasonics, a dog will bark panicly, though no one is seen near.
• I understood this after studying about ‘range of hearing the sound’.
• Before the knowledge of ‘range of hearing the sound’, I felt that the dogs are barking by seeing some devils, which is a misconception.
• Scientific knowledge helps us to know reasons for many misconcepts.

Question 29.
Find out the names of animals (and their photographs from internet) which communicate using infra-sonic or ultra-sonic sound and prepare a scrap book.
Answer:
Scrap book

 

9th Class Physical Science 11th Lesson Sound InText Questions and Answers

9th Class Physical Science Textbook Page No. 184

Question 1.
How does sound reach our ears from the source of its production?
Answer:
Soufid travels in the form of waves. It reaches our ears from the source of its production, in the form of waves.

Question 2.
Does it travel by itself or is there any force bringing it to our ears?
Answer:
Sound does not travel by itself. When a sound is produced, the kinetic energy of the source, vibrates the nearest particles in the medium. These particles transfers energy and finally, it reaches our ears.

Question 3.
What is sound? Is it a force or an energy?
Answer:
Sound is a form of energy.

Question 4.
Why don’t we hear sounds when our ears are closed?
Answer:
When our ears are closed, the energy in the form of waves reaches our ear, but it cannot make the eardrum to vibrate. Hence we cannot hear the sound.

Question 5.
Why is the light ray dancing, after sound is made in the tin?
Answer:
The dancing of light ray, after the sound is made in the tin shows that the sound travels in the form of waves from the source of its production.

Question 6.
What do you infer from this?
Answer:
Sound is a form of energy which can travel in the form of waves through the medium.

Question 7.
Can we say that sound is a form of mechanical energy?
Answer:
Yes, sound is a form of mechanical energy.

9th Class Physical Science Textbook Page No. 185

Question 8.
Do you hear any sound?
Answer:
We cannot hear any sound.

Question 9.
Do you see any vibrations in the tuning fork?
Answer:
Yes, we can sense the vibrations in the tuning fork.

Question 10.
What do you conclude from the above activity?
Answer:
We observe that vibrating tuning fork produces sound.

Question 11.
Can you produce sound without vibration in the body?
Answer:
We cannot produce sound without vibration in the body.

Question 12.
Give some examples of vibrating bodies which produce sound.
Answer:
Drums, tabla, calling bell, school bell, etc.

Question 13.
What part of our body vibrates when we speak?
Answer:
When we speak, vocal cord vibrates in our body.

Question 14.
Do all vibrating bodies necessarily produce sound?
Answer:
All vibrating bodies produce sound, but we cannot hear some of them, due to the limit of audible frequency.

9th Class Physical Science Textbook Page No. 186

Question 15.
If sound travels in the form of a wave then what is the pattern?
Answer:
Sound travels in the form of longitudinal or transverse waves in the air or in the other material.

9th Class Physical Science Textbook Page No. 188

Question 16.
What do you say about sound waves in air by the above activity?
Answer:
From the above activity, we can say that there involves change in the density of medium while sound waves are travelling in air.

Question 17.
Are they longitudinal or transverse?
Answer:
Sound waves in air are longitudinal.

Question 18.
Does sound get reflected at the surface of a solid?
Answer:
Yes, sound gets reflected at the surface of a solid as in the case of reflection of light.

Question 19.
What happens if you lift your tube slightly above the table?
Answer:
If we lift the tube slightly we cannot hear the sound clearly.

Question 20.
Are able to listen to the sound? If not why?
Answer:
We are unable to hear the sound. If we lift one of the pipes then the pipe carrying incident sound, the pipe carrying reflected sound will not be in the same plane. Hence we cannot hear the sound.

9th Class Physical Science Textbook Page No. 195

Question 21.
Do hard surfaces reflect sound better than soft ones?
Answer:
Generally, hard surfaces reflect sound better than soft surfaces. But sound reflects quite well from rough surfaces than polished surfaces.

9th Class Physical Science Textbook Page No. 187

Question 22.
Do compressions and rarefactions in sound wave travel in same directions or in opposite directions? Explain.
Answer:

• Compressions and rarefactions in a sound wave will be in opposite direction.
• In a compression, all the particles come close, so the density and pressure increases.
• In a rarefaction, all particles drag back, so the density and pressure decreases.
• In a microscopic view of particle, the compression and rarefaction travel in opposite directions.

9th Class Physical Science Textbook Page No. 191

Question 23.
Does the frequency of sound waves depend on the medium in which it frawels? How?
Answer:
Yes.

2) As speed of wave differs from medium to fnedium, the frequency also changes, keeping the wavelengths constant.

Question 24.
The frequency of source of sound is 10 Hz. How many times does it vibrate in one minute?
Answer:
Number of vibrations per second = 10
Number of vibrations in one minute = 10 × 60 = 600

Question 25.
Gently strike a hanging bell (temple bell) and try to listen to the sound produced by it with a stethoscope keeping it both at bottom portion and top portion of the bell. Is the pitch and loudness of the sound same at the two portions? Why?
Answer:
No. The bob of the bell strikes at the bottom portion of the bell. Hence the pitch and loudness are high.

Question 26.
During a thunderstorm if you note a 3 second delay between the flash of lightning and sound of thunder. What is the approximate distance of thunderstorm from you ?
Answer:
Time taken to reach the sound = 3 s ; Speed of sound in air = 343.2 m/sec.
Distance of thunderstorm = 343.2 x 3 = 1029.6 m

9th Class Physical Science Textbook Page No. 194

Question 27.
Two girls are playing on identical stringed instruments. The strings of the both instruments are adjusted to give notes of same pitch. Will the quality of two notes be same? Justify your answer.
Answer:
If the two girls are playing with same instruments, then the quality is same. If the girls are playing with different stringed instruments the quality will be different.

Quality is the characteristic which enables us to distinguish between musical notes emitted by different musical instruments.

Question 28.
What change, would you expect in the characteristic of a musical sound when we increase its frequency one instance and amplitude in another instance?
Answer:
When frequency is increased, the pitch of sound increases. When amplitude is increased, its loudness increases.

9th Class Physical Science Textbook Page No. 195

Question 29.
What could be the reason for better reflection of sound by rough surfaces than polished surfaces?
Answer:

• Sound reflects better on rough surfaces than polished surfaces.
• The rough surface reflects sound in all directions, so it can reach in many directions.

9th Class Physical Science Textbook Page No. 196

Question 30.
Why is an echo weaker than the original sound?
Answer:

• Echo is the reflected sound.
• While it travels back, it gradually loses its energy.
• Hence the echo is weaker than original sound.

Question 31.
In a closed box if you say hello, the sound heard will be Hellooooo ………. What does it mean?
Answer:
In a closed box, the multiple reflections of sound has no way to go out side. Hence we will hear the sound as hellooooooo ………

9th Class Physical Science Textbook Page No. 197

Question 32.
What is the advantage of having conical openings in horns, megaphones, etc?
Answer:
The conical openings in horns, megaphones, etc. will guide the reflected sound waves in forward direction and spreads towards the audience.

Question 33.
Why do we put cushions on the chairs, carpet on the floor, straw materials on the walls in cinema halls?
Answer:

• These materials absorb unnecessary reflections of sound, so that we can hear more clearly.
• As these material absorb reflected sound waves, the people outside the cinema halls, cannot hear the sound produced in the cinema hall.

9th Class Physical Science Textbook Page No. 199

Question 34.
What is the benefit of using ultrasound over light waves in the above applications?
Answer:

• Light waves cannot penetrate in the internal organs like liver, kidney, etc.
• Light wave after reflection do not form image.
• Ultrasound waves can penetrate through internal organs like liver, kidney, etc.
• After reflection, ultrasound waves produce image. So, in ultrasonography and surgeries, ultrasound waves are better than light waves.

9th Class Physical Science 11th Lesson Sound Activities

Activity 1

Question 1.
How can .you say that the sound is a form of energy?
Answer:

1. Take a tin can and remove both ends to make a hollow cylinder.
2. Take a balloon and stretch it over the can.
3. Wrap a rubber band around the balloon.
4. Take a small mirror and stick it on the balloon.
5. Take a laser light and let it fall on the mirror.
6. After reflection the light spot is seen on the wall.
7. Now shout directly into the open end of the can and observe the dancing light.

Observations:

1. When sound is made, the energy produced from the sound vibrates the membrane of the balloon, resulting in the dancing of light ray.
2. This shows that sound is a form of energy which travels in air.

Activity – 2

Question 2.
Prove that the sound is produced from a vibrating source.
Answer:

1. Attach a small piece of steel wire to one of the prongs of a tuning fork as shown in the figure.
2. Strike the tuning fork with a rubber hammer.
3. While it is vibrating, try to draw a straight line on a piece of smoked glass as quick as possible with, it.
4. Keep the end of the wire in such a way just it touches the glass.
5. A line is formed in the form of a wave.
6. Repeat the experiment when the tuning fork is not vibrating and observe the difference in the line.

Observations:

1. We have produced vibrations in the tuning fork by striking it with a hammer.
2. Thus the vibrating tuning fork produces sound.
3. Thus the sound is produced by vibrating bodies.

Activity – 3

Question 3.
а) How do you demonstrate the formation of compressions and rarefactions in a slinky?
Answer:

 

1. Take a slinky.
2. It is a spring-shaped toy which can be extended or compressed very easily.
3. Lay it down on a table or the floor as shown in figure.
4. Ask a friend to hold one end.
5. Pull the other end to stretch the slinky and then move it to and fro along its length.
6. We will see alternate compressions and rarefactions of the coil.
7. This is similar to the pattern of varying density produced in a medium when sound passes through it.

b) Mow do you demonstrate the formation of crests and troughs in a slinky?
Answer:

1. Hang a slinky from a fixed support.
2. Hold it gently at the lower end and quickly move your hand sideways and back.
3. This will cause a hump on the slinky near the lower end.
4. The hump travels upwards on the slinky as shown in the figure.
5. The humps formed alternately are known as crests and troughs.

Activity – 4

Question 4.
Describe an activity to listen the reflected sound.
Answer:

1. Take two long, identical tubes and place them on
2. Ask your friend to speak softly into one tube while you use the other tube to listen.
3. Adjust the tube until you hear the best sound.
4. You will find that you hear your friend’s voice best when the tube makes equal angles with a normal to the wall.
5. This shows that reflection of sound follows the laws of reflection of light.
6. Lift your tube slightly above the table.
7. You will not be able to listen the voice clearly, because the plane carrying the incident wave and reflected wave are changed.
8. Repeat the experiment by placing flat objects of different materials (steel and plastic trays, a card board, a tray wrapped with cloth, etc.) against the wall and observe the changes in the sound.

Observations:

1. Reflection of sound follows the laws of reflection of light.
2. When the plane carrying incident wave and reflecting wave changes, the reflected sound cannot be heard clearly.
3. Hard or rough surfaces reflect the sound better than soft surfaces.

AP State Syllabus AP Board 9th Class Physical Science Solutions Chapter 6 Chemical Reactions and Equations Textbook Questions and Answers.

AP State Syllabus 9th Class Physical Science Solutions 6th Lesson Chemical Reactions and Equations

9th Class Physical Science 6th Lesson Chemical Reactions and Equations Textbook Questions and Answers

Improve Your Learning

Question 1.
What is a balanced chemical equation? Why should chemical equations be balanced?
Answer:
1) A chemical equation in which the number of atoms of different elements on the reactants side (left side) are same as those on product side (right side) is called a balanced chemical equation.
Ex : Zn + 2HCl → ZnCl₂ + H₂ ↑

2) All the chemical equations must balance because atoms are neither created nor destroyed in chemical reactions.

3) The number of atoms of each element before and after reaction must be the same.

4) According to the law of conservation of mass, the total mass of the substances that are taking part in a chemical reaction must be the same before and after the reaction.

Question 2.
Balance the following chemical equations.
a) NaOH + H₂SO₄ → Na₂SO₄ + H₂O
b) Hg (NO₃)₂ + KI → Hgl₂ + KNO₃
c) H₂ + O₂ → H₂O
d) KClO₃ → KCl + O₂
e) C₃H₈ + O₂ → CO₂ + H₂O
Answer:
a) 2NaOH + H₂SO₄ → Na₂SO₄ + 2H₂O
b) Hg (NO₃)₂ + 2 KI → Hgl₂ + 2KNO₃
c) 2H₂ + O₂ → 2H₂O
d) 2KClO₃ → 2KCl + 3O₂
e) C₃Hg + 5O₂ → 3CO₂ + 4H₂O

Question 3.
Write the balanced chemical equations for the following reactions.
a) Zinc + Silver nitrate → Zinc nitrate + Silver
b) Aluminium + Copper chloride → Aluminium chloride + Copper
c) Hydrogen + Chlorine → Hydrogen chloride
d) Ammonium nitrate → Nitrous Oxide + Water
Answer:
a) Zn + 2AgNO₃ → Zn(NO₃)₂ + 2Ag
b) 2Al + 3CuCl₂ → 2AlCl₃ + 3Cu
c) H₂ + Cl₂ → 2HCl
d) NH₄NO₃ → N₂O + 2H₂O

Question 4.
Write the balanced chemical equations for the following and identify the type of reaction in each case.
a) Calcium hydroxide(aq) + Nitric acid(aq) → Water(l) + Calcium nitrate(aq)
b) Magnesium(sJ + Iodine → Magnesium Iodide(s)
c) Magnesium(s) + Hydrochloric acid(aq) → Magnesium chloride(aq) + Hydrogen^
d) Zinc(s) + Calcium chloride(aq) → Zinc Chloride(aq) + Calcium(s)
Answer:
a) Ca(OH₂) + HNO₃ → H₂O + Ca(NO₃)₂
This is double decomposition reaction.

b) Mg + I₂ → Mgl₂
This is chemical combination reaction.

c) Mg + 2HCl → MgCl₂ + H₂ ↑
This is chemical displacement reaction.

d) Zn + CaCl₂ → ZnCl₂ + Ca
This is chemical displacement reaction. This reaction is not possible, because calcium is more reactive than zinc.

Question 5.
Write an equation for decomposition reaction where energy is supplied in the form of heat / light / electricity.
Answer:
Chemical decomposition reaction : A chemical reaction in which a single substance splits into two or more substances is called chemical decomposition.
For decomposition reaction energy is supplied in the form of :

Question 6.
What do you mean by precipitation reaction?
Answer:
A reaction in which insoluble substance in water is formed as product is called precipitation reaction.

Question 7.
How does chemical displacement reactions differ from chemical decomposition reaction? Explain with an example for each.
Answer:

Question 8.
Name the reactions taking place in the presence of sunlight.
Answer:
1) In the presence of sunlight plants prepare their food by taking C02 from the air and H20 from the soil with their chloroplasts of the green leaves. This reaction is called photosynthesis.

Question 9.
Why does respiration considered as an exothermic reaction? Explain.
Answer:

• We need energy to stay alive.
• We get this energy from food we eat.
• During digestion, food is broken down into simpler substances.
• For example, rice and potato contains starch.
• The starch breaks down to form glucose.
• This glucose combines with oxygen in the cells of our body and releases energy, which helps to do the various works.
• During this process, energy is given out. Hence this reaction can be called exothermic reaction.
• The special name of this reaction is respiration.
• So respiration is considered as exothermic reaction.
• C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + Q (Energy)

Question 10.
What is the difference between displacement and double displacement reactions? Write equations for these reactions.
Answer:

Chemical displacement reaction	Chemical double displacement reaction
1. In a reaction when an active element displaces less active element from its compound is called displacement reaction.	1. If two reactants exchange their constituents chemically and form two products, then the reaction is called as double displacement reaction.
2. Zn + 2HCl → ZnCl2 + H2 In this example Zn displaces Hydrogen from HCl.	2. Na2SO4 + BaCl2 → BaSO4 + 2NaCl In this reaction SO42- and Cl– are mutually exchanged.
3. General formula to the reaction is A + BC → AC + B	3. General formula to the reaction is AB + CD → AD + BC

Question 11.
MnOz + 4HCl → MnCl₂ + 2H₂O + Cl₂ ↑
In the above equation, name the compound which is oxidized and which is reduced.
Answer:
In the above equation, HCl compound is oxidized and MnO₂ is reduced.

Question 12.
Give two examples for oxidation-reduction reaction.
Oxidation :
Oxidation is a reaction that involves the addition of oxygen or loss of hydrogen or electrons.

Reduction :
The process in which a substance loses oxygen or gains hydrogen or electrons is known as reduction.

Question 13.
In the refining of silver, the recovery of silver from silver nitrate solution involved displacement by copper metal. Write the reaction involved.
Answer:

• Cu_(s) + 2 AgNO_3(aq) > Cu(NO₃)_2(aq) + 2Ag_(s)
• This is redox reaction, copper is the reducing agent and the silver is reduced.
• Electrons from the copper metal are transferred to the silver.
• This reaction can also be called a displacement reaction because copper displaces silver as it is more reactive.

Question 14.
What do you mean by corrosion? How can you prevent it?
Answer:

• When some metals are exposed to moisture, acids, etc. they tarnish due to the formation of respective metal oxide on their surface. This process is called “corrosion”.
• Corrosion can be prevented by painting, oiling, greasing, galvanizing, chrome plating or making alloys.
• Galvanizing is a method of protecting iron from rusting by coating them a thin layer of zinc.

Question 15.
Explain rancidity.
Answer:

• Oxidation reactions in food material that were left for a long period are responsible for spoiling of food. This process is called “rancidity”.
• When these processes occur in food, undesirable odours and flavours can result.
• Rancidity is an oxidation reaction.

Question 16.
Balance the following chemical equations including the physical states,
a) C₆H₁₂O₆ → C₂H₅OH + CO₂
b) Fe + O₂ → Fe₂O₃
c) NH₃ + Cl₂ → N₂H₄ + NH₄Cl
d) Na + H₂O → NaOH + H₂
Answer:
a) C₆H₁₂O_6(s) → C₂H₅OH_(l) + CO_2(g)
b) Fe_(s) + O_2(g) → Fe₂O_3(s)
c) NH_3(aq) + Cl_2(g) → N₂H_4(l) + NH₄Cl_(aq)
d) 2Na_(s) + 2H₂O_(l) → NaOH + H₂

Question 17.
Balance the chemical equation by including the physical states of the substances for the following reactions.
a) Barium chloride and Sodium sulphate aqueous solutions react to give insoluble Barium sulphate and aqueous solution of Sodium chloride.
b) Sodium hydroxide reacts with Hydrochloric acid to produce Sodium chloride and water.
c) Zinc pieces react with dilute Hydrochloric acid to liberate Hydrogen gas and forms Zinc chloride.
Answer:
a) BaCl_2(aq) + Na₂SO_4(aq) → BaSO_4(s)↓ + NaCl_(aq)
b) NaOH_(aq) + HCl_(aq) → NaCl_(aq) + H₂O_(l)
c) Zn_(s) + 2HCl_(aq) → ZnCl_2(aq) + H_2(g)

Question 18.
A shiny brown coloured element ‘X’ on heating in air becomes black in colour. Can you predict the element ‘X’ and the black coloured substance formed? How do you support your predictions?
Answer:
The brown coloured element is copper (Cu). On heating copper reacts with oxygen
present in the atmosphere to form copper oxide which is black in colour.
The reaction is shown below.

If we pass hydrogen gas over hot copper oxide we will notice that black coating on copper turns brown because copper oxide loses oxygen to form copper.
This will support our prediction.

Question 19.
Why do we apply paint on iron articles?
Answer:

• Ferrous reacts with oxygen in the air and form iron oxide.
  2 Fe + O₂ → 2 FeO
• This reaction is called corrosion. It spoils the iron articles by rusting.
• Corrosion of iron articles can be prevented or minimized by shielding the metal surface from oxygen and moisture.
• It can be prevented by applying paint on the articles.

Question 20.
What is the use of keeping food in air tight containers?
Answer:

• Oxidation is defined as the interaction of oxygen molecules with all the different substances from metal to living tissue which may come into contact with it.
• When fats and oils are oxidized they become rancid. Their smell and taste change.
• Keeping food in airtight containers helps to slow down oxidation process.
• So, manufacturers of potato chips usually flush bags of chips with gas such as nitrogen to prevent the chips from getting oxidized.

Fill in the Blanks

1. The decomposition of vegetable into compost is an example of ……………. reaction.
2. The chemical reaction in which energy is absorbed to form a new compound is called ………….
3. The reaction 2N₂O → 2N₂ + O₂ is an example for ………….. reaction.
4. The reaction Ca + 2H₂O → Ca(OH)₂ + H₂ ↑ is an example for ………….. reaction.
5. The substances that are present on left side of a chemical equation are called
6. The arrow mark between the products and reactants of a chemical equation shows of the reaction.
Answer:

1. oxidation
2. endothermic reaction
3. decomposition
4. displacement
5. reactants
6. direction

7. Match the following :

1) 2AgNO3 + Na2CrO4 → Ag2CrO4 + 2NaNO3	a) combination reaction
2) 2NH3 → N2 + 3H2	b) decomposition reaction
3) C2H4 + H2O → C2H6O	c) displacement reaction
4) Fe2O3 + 3CO → 2Fe + 3CO2	d) double displacement reaction

Answer:

1) 2AgNO3 + Na2CrO4 → Ag2CrO4 + 2NaNO3	d) double displacement reaction
2) 2NH3 → N2 + 3H2	b) decomposition reaction
3) C2H4 + H2O → C2H6O	a) combination reaction
4) Fe2O3 + 3CO → 2Fe + 3CO2	c) displacement reaction

Multiple Choice Questions:

1. Fe₂O₃ + 2Al → Al₂O₃ + 2Fe
The above reaction is an example of:
A) Combination reaction
B) Decomposition reaction
C) Displacement reaction
D) Double decomposition reaction
Answer:
C) Displacement reaction

2. What happens when dil. hydrochloric acid is added to iron filings? Choose the correct answer.
A) Hydrogen gas and iron chloride are produced.
B) Chlorine gas and iron hydroxide are produced.
C) No reaction takes place.
D) Iron salt and water are produced.
Answer:
A) Hydrogen gas and iron chloride are produced.

3. 2PbO_(s) + C_(s) → 2Pb_(s) + CO_2(g)
Which of the following statements are correct for the above chemical reaction?
i) Lead is reduced
ii) Carbon dioxide is oxidized
iii) Carbon is oxidized
iv) Lead oxide is reduced
A) (i) and (ii)
B) (i) and (iii)
C) (i), (ii) and (iii)
D) all
Answer:
B) (i) and (iii)

4. The chemical equation
BaCl₂ + Na₂SO₄ → BaSO₄ + 2NaCl represents following type of chemical reaction.
A) displacement
B) combination
C) decomposition
D) double-displacement
Answer:
D) double-displacement

5. The reaction of formation hydrogen chloride from hydrogen and chlorine repre¬sents following type of chemical reaction i
A) decomposition
B) displacement
C) combination
D) double-displacement
Answer:
C) combination

9th Class Physical Science 6th Lesson Chemical Reactions and Equations InText Questions and Answers

9th Class Physical Science Textbook Page No. 90

Question 1.
What changes do you notice generally?
Answer:
I noticed two types of changes generally. They are :

1. Physical change,
2. Chemical change.

Question 2.
“Coal is burnt”, “crackers are burnt” ………. changes Are they physical changes (or) chemical changes?
Answer:
They are all chemical changes.

Question 3.
Are they (coal, crackers) temporary changes or permanent changes?
Answer:
They are permanent changes.

Question 4.
How do we know a chemical reaction has taken place?
Answer:
While we observe the following things, we can conclude that a chemical reaction has taken place.

1. A change that changes state and colour of substance.
2. A change that releases heat energy.
3. A change which forms an insoluble substance as precipitate.
4. A change that liberates a gas.

9th Class Physical Science Textbook Page No. 92

Question 5.
Do the atoms of each element on left side equal to the atoms of the element on the right side of the equation?
Answer:
Yes. The atoms of each element in left side are equal to the atoms of their corresponding element.

9th Class Physical Science Textbook Page No. 94

Question 6.
Are the atoms of all elements of reactants present in products?
Answer:
Yes. The atoms of all elements of reactants are present in products.

Question 7.
2 C₃H₈ + 10 O₂ → 6 CO₂ + 8 H₂O.
Is it a well balanced equation as per rules ? How do you say?
Answer:
Yes, it is a balanced equation.

L.H.S.	R.H.S.
Number of ‘C’ atoms = 6	Number of ‘C’ atoms = 6
Number of ‘H’ atoms = 16	Number of ‘H’ atoms = 16
Number of ‘O’ atoms = 20	Number of ‘O’ atoms = 20

9th Class Physical Science Textbook Page No. 105

Question 8.
Did you notice the colour coating on silver and copper articles?
Answer:
Yes. I noticed. To prevent from corrosion they are colour coated like that.

9th Class Physical Science Textbook Page No. 106

Question 9.
How can we prevent the spoiling of food?
Answer:
The spoilage of food can be prevented by adding preservatives like vitamin C and vitamin E.

9th Class Physical Science 6th Lesson Chemical Reactions and Equations Activities

Activity – 1

Question 1.
Write an activity when calcium oxide reacts with water.
What type of reaction is this ? Write balanced chemical equation.
Answer:

1. Take about 1 gm of quick lime (CaO) in a beaker.
2. Add 10 ml of water to this.
3. Touch the beaker with your finger.
4. The beaker is hot.
5. The reason is that the calcium oxide reacts with water and releases heat energy.
6. Calcium oxide dissolves in water producing colourless solution [Ca(OH)2],
7. Dip the red litmus paper in it.
8. Red litmus paper changes into blue colour.
9. We conclude that the solution obtained is a basic solution.
10. It is a chemical combination reaction.
    CaO_(s) + H₂O_(l) → Ca(OH)₂

Activity – 2

Question 2.
What change do you observe by mixing of sodium sulphate solution and barium chloride solution?
(OR)
Which type of reaction is this (mixing of sodium sulphate and barium chloride solutions)?
Answer:

• Take about 100 ml of water in a beaker.
• Dissolve a small quantity of sodium sulphate (Na₂SO₄) in it.
• Take about 100 ml of water in another beaker.
• Dissolve a small quantity of barium chloride (BaCl₂) in it.
• Add these (Na₂SO₄, BaCl₂) two solutions.
• We will get a white precipitate of barium sulphate.
  Na₂SO₄ + BaCl₂ → BaSO₄↓ + 2NaCl
• It is a double displacement reaction.

Activity – 3

Question 3.
Formation of H₂ gas by the action of dil. HCl and Zn pieces.
(OR)
What happens if dilute HCl is added to zinc granules. Explain the process with an experiment. What type of reaction is this? Write the balanced chemical equation for this process.
Answer:

Hydrogen gas experiment:

1. Take a few zinc granules in a conical flask.
2. Add about 5 ml of dilute hydrochloric acid to the conical flask.
3. Observe the changes in the conical flask.
4. Keep a burning matchstick near the mouth of the conical flask.
5. The light of burning matchstick is put off with ‘pop’ sound.
6. This indicates the H₂ gas has released in this reaction.
7. When we touch the bottom of the conical flask with our finger, we feel hot.
8. So, this reaction produces heat.
9. It is a displacement reaction
   Zn_(s) + 2HCl_(aq) → ZnCl_2(aq) + H_2(g)

Activity – 4 Chemical Combination

Question 4.
Write an activity on burning of magnesium ribbon in the presence of air.
(OR)
Write an activity which shows burning of magnesium ribbon is a chemical combination reaction.
Answer:

1) Take about 3 cm long piece of magnesium ribbon.
2) Rub the magnesium ribbon with sand paper.
3) Hold it with a pair of tongs.
4) Burn it with a spirit lamp or burner.
5) Magnesium burns in oxygen by producing dazzling white flame and changes into white powder (magnesium oxide).

7) In this reaction magnesium and oxygen combine to form a new substance magnesium oxide.
8) A reaction in which single product is formed from two or more reactants is known as chemical combination reaction.

Activity – 5 Decomposition Reaction

Question 5.
How can you prove that CO₂ is released on heating CaCO₃?
(OR)
When calcium carbonate is heated it releases certain gas. What is the gas that has been released? How do you identify that gas? Write the activity of this reaction.
Answer:

• Take a pinch of Calcium Carbonate (lime stone) in a boiling tube.
• Heat the boiling tube over the flame of spirit lamp or burner.
• Now take a burning matchstick near the mouth of delivery tube.

Heating of calcium carbonate and testing the gas evolved with burning matchstick

• We can observe that the matchstick kept near the mouth of the boiling tube will be put off.
• In the above activity, on heating CaC03, it decomposes to Calcium oxide (CaO) and Carbon dioxide (CO₂).
  
• When a decomposition reaction is carried out by heating, it is called thermal decomposition reaction.

Activity – 6

Question 6.
Write an activity to show that nitrogen dioxide (NO^ is released by heating of lead nitrate.
(OR)
Write an activity which shows thermal decomposition reaction.
Answer:

1. Take about 0.5 g of lead nitrate powder in a boiling test tube.
2. Hold the boiling tube with a test tube holder.
3. Heat the boiling tube over a flame.
4. We observe that on heating of lead nitrate brown fumes of nitrogen dioxide are released.
5. On heating lead nitrate, it decomposes and gives lead oxide, oxygen and nitrogen dioxide.

6) Reaction :

7) This is also an example for thermal decomposition reaction.

Activity – 7

Question 7.
Write an activity to show dissociate of water into hydrogen and oxygen.
(OR)
Write an activity showing decomposition of a compound in the presence of electricity.
(OR)
Draw a neat diagram representing electrolysis of water.
How do you prove that water contains hydrogen and oxygen in the ratio of 2 : 1?
(OR)
Explain electrolysis of water.
(OR)
What are the materials required for the experiment to show the chemical decomposition of water ? Write the procedure of the experiment. Name the products which we get in this reaction.
(OR)
Draw a neat diagram showing the electrolytic decomposition reaction of water. Write the balanced chemical equation of the above reaction.
Answer:

1. Take a plastic mug.
2. Drill two holes at its base.
3. Fit two ‘one holed rubber stoppers’ in these holes.
4. Insert two graphite electrodes in these rubber stoppers.
5. Connect the electrodes to 9V battery.
6. Fill the mug with water, so that the electrodes are immersed.
7. Add few drops of dilute sulphuric acid to water.
8. Take two test tubes filled with water and invert them over the two graphite electrodes.
9. Switch on the current and leave the apparatus undisturbed for sometime.
10. We will notice that the liberation of gas bubbles at both the electrodes.
11. These bubbles displace the water in the test tubes.
12. We also observe that the volume of gas collected in the both test tubes is different.
13. Once the test tubes are filled with gases take them out carefully.
14. Test both the gases separately by bringing a burning candle near the mouth of each test tube.
15. The gas which occupies high volume makes to burn with blue flame and put off candle flame with ‘puf sound is hydrogen gas.
16. The gas which occupies low volume and makes to burn candle brightly is oxygen gas.
17. In the above activity on passing the electricity, water dissociates to hydrogen and oxygen gases. This is called electrolytic composition reaction.
    

Activity – 8

Question 8.
Write an activity to observe silver bromide decomposes in the presence of sunlight.
(OR)
Write an activity for photochemical reaction.
Answer:

• Take some quantity of silver bromide on a watch glass.
• When we observe the colour of silver bromide it is light yellow in colour.
• Place the watch glass in sunlight for sometime.
• Silver bromide decomposes to silver and bromine in sunlight.
• After sometime we observe that the colour of silver bromide changes into grey colour.

• Light yellow coloured AgBr changes into Ag and Br.
• This decomposition reaction occurs in the presence of sunlight and such reactions are called photochemical reactions.
• The above decomposition reactions require some energy to convert reactants to products.
• This type of reactions are called endothermic reactions.
• 

Activity – 9

Question 9.
Write an activity to show that zinc displaces hydrogen from dil. hydrochloric acid.
Answer:

1. Take a small quantity of zinc dust in a conical flask.
2. Add dilute hydrochloric acid slowly.
3. Now take a balloon and tie it to the mouth of the conical flask.
4. We can observe that the gas bubbles coming out from the solution and the balloon bulges out.
5. Zinc pieces react with dilute hydrochloric acid and liberate hydrogen gas.
6. The element zinc has displaced hydrogen from dilute hydrochloric acid. This is one of the examples for displacement reaction.
7. Equation : Zn_(s) + 2 HCl_(aq) → ZnCl_2(aq) + H_2(g) ↑

Activity – 10

Question 10.
Write an activity to show that iron displaces copper from copper sulphate.
(OR)
Write an activity about how you conduct an experiment to show that more reactive metals replace less reactive metals from their compounds. (OR)
Why is an iron nail kept in a solution brownish? Explain the activity.
Answer:

1. Take two iron nails and clean them by rubbing with sand paper.
2. Take two test tubes and mark them as A and B.
3. Take about 10 ml of copper sulphate solution in each test tube.
4. Dip one iron nail in copper sulphate solution of test tube A.
5. Keep the test tube with iron nail undisturbed for 20 minutes.
6. Keep the other iron nail and test tube aside. ;
7. Compare the colours of the solutions in the test tubes.
8. Now take out the iron nail from copper sulphate solution.
9. Keep the iron nail and test tubes A and B side by side.
10. Compare with the other iron nail that has been kept aside.
11. We will observe that the iron nail dipped in copper sulphate solution becomes brownish.
12. Blue colour of copper sulphate solution in test tube ‘A’ fades.
13. Iron is more reactive than copper, so it displaces copper from copper sulphate.
14. This is one of the examples for displacement reaction.
15. Equation : Fe_(s) + CuSO_4(aq) → FeSO_4(aq) + Cu_(s)

Activity – 11 Double displacement reaction

Question 11.
Write an activity for the formation of lead iodide and potassium nitrate.
(OR)
Your friend has a doubt about chemical double displacement reaction. How can you clarify his/her doubt by showing an experiment? Explain.
(OR)
What happens if lead nitrate solution is added to potassium iodide solution? Explain the activity.
Answer:

It forms yellow precipitate of lead iodide.

1. Take a pinch of lead nitrate and dissolve in 5.0 ml of distilled water in a test tube.
2. Take a pinch of potassium iodide in another test tube and dissolve in distilled water.
3. Mix lead nitrate solution with potassium iodide solution.
4. We observe that a yellow coloured substance which is insoluble in water, is formed.
5. This insoluble substance is known as precipitate.
6. The precipitate is Lead Iodide.
7. Equation : Fb(NO₃)_2(aq) + 2 KI_(aq) → Pbl_2(s) + 2KNO_3(aq)
8. In the above reaction, lead ion and potassium ion exchange their places each other.
9. Lead ion combines with iodide ion and forms Pbl2 as precipitate and KN03 remains in the solution.
10. Such reaction is double displacement reaction.

Activity – 12

Question 12.
Write an activity to show that the oxidation of copper to copper oxide.
(OR)
Write an activity for example of oxidation and reduction.
Answer:

• Take about 1.0 gram of copper powder in a China dish.
• Keep the China dish on a tripod stand containing wire gauze.
• Heat it with a bunsen burner or with a spirit lamp.
• We can find that the surface layer of copper becomes black.
• On heating copper reacts with oxygen present in the atmosphere to form copper oxide.

•  Here copper combines with oxygen to form copper oxide.
• Here oxygen is gained and the process is called oxidation.
• Now pass hydrogen gas over hot copper oxide.

• We can observe that the black coating on copper turns brown because copper oxide loSes oxygen to form copper.
• In this process oxygen is lost and the process is called ”Reduction”.

SCERT AP Board 9th Class Social Solutions 15th Lesson Industrialisation and Social Change Textbook Questions and Answers.

AP State Syllabus 9th Class Social Studies Solutions 15th Industrialisation and Social Change

9th Class Social Studies 15th Lesson Industrialisation and Social Change Textbook Questions and Answers

Improve Your Learning

Fill in the blanks with correct options :
Question 1.
Britain did not depend on different parts of the world for ________ and ________ (labourers; raw material; capital; inventions)
Answer:
labourers, capital

Question 2.
Two important types of transport during the Industrial revolution were ________ and ________ (road, air, water, rail)
Answer:
water, rail

Question 3.
Write two sentences each on following aspects in the context of Industrial revolution:
a) Technology
b) Financing and money
c) Agriculture revolution
d) Transport systems
Answer:
a) Technology :
The commencement of industrial revolution is closely linked to a small number of innovations, beginning in the second half of the 18th century. By the 1830s the following gains had been made in important technologies, e.g. : Textiles, steam power and iron making.

b) Financing and money:
The whole industrial revolution got founded by a few people who held power to issue essentially infinite credit. Most new industries were financed by small investors, merchants, shopkeepers and farmers.

c) Agriculture Revolution :
The Agriculture Revolution was period of agriculture development between 18th and the end of 19th century, which saw a massive and rapid increase in agricultural productivity and vast improvement in farm technology. Many inventions were created and improved during this revolution.

d) Transport Systems :
The growth of industrial revolution developed on the ability to transport raw materials and finished goods over long distances. These facilities were of three main types – Water ways, Roadways and Rail roads.
Out of these three, water transportation was the cheapest.

Question 4.
What do you think is special about inventions happening during the industrial revolution ?
Answer:

• Most inventions were more the product of determination, interest, curiosity, even luck, than the application of scientific knowledge.
• Some inventors in the cotton industry, like John Kay and James Hargreaves, were familiar with the skills of weaving and carpentry.
• Richard Arkwright, however, was a barber and wig-maker, Samuel Crompton was not technically skilled and Edmund Cartwright studied literature, medicine and agriculture, initially wished to become a clergyman and knew little of mechanics.
• By contrast, in the area of steam engines, Thomas Savery, an army officer, Thomas Newcomen, a blacksmith and locksmith, and James Watt, with a strong mechanical bent, all had some knowledge relevant to their inventions.
• The road-builder John Metcalf, who personally surveyed surfaces for roads and planned them, was blind.
• The canal builder James Brindley was almost illiterate, with such poor spelling that he could never spell the word ‘navigation’, but he had tremendous powers of memory, imagination and concentration.

Question 5.
How were the lives of different classes of British women affected by the Industrial revolution?
(OR)
“All classes of British women were affected by the industrial revolution” Write your comments.
Answer:

• The Industrial Revolution was a time of important changes in the way that women worked.
• The village women were actively involved in farm work, they reared livestock, gathered firewood and spun yarn on spinning wheels in their homes.
• Their earnings were necessary to supplement men’s meagre wages.
• Women were the main workers in the silk, lace making and knitting industries, as well as in the metal industries of Birmingham.
• Women may well have gained increased financial independence and self-esteem from their jobs; but this was more than offset by the humiliating terms of work they endured.
• Most classes eventually benfited in some way from the huge profits.
  Thus the lives of different classes of British women were affected by the industrial revolution.

Question 6.
What were the relative advantages of canal and railway transportation?
Answer:

• It is easy to shipping goods.
• Both are cheap means of transport when compared to roadways.
• Bulk quantity of goods can be transhipped.

Question 7.
Locate the places where iron and textile Industries are mainly concentrated in England during Industrial revolution.
Answer:

Question 8.
Prepare a table on invention during the time of Industrial Revolution.
Answer:

Inventions	Inventors
Cotton – textile
1. Flying shuttle – 1733	John Kay
2. Waterpowered loom – 1784	Edmud Cartwright
3. Spinning Jenny – 1764	James Hargreaves
4. Spinning mule – 1779	Samuel Crompton
5. Cotton gin – 1794	Eli Whitney
6. The Factory system – 18th Century	Richard Arkwright
7. Stem engine – 1712	James Watt
8. Steam boat – 1786	Robert Fulton
9. Rail roads – 1869	George Stephenson
10. Steel making – 1855	Henry Bessemer
11. Electricity and the light bulb – 1879	Thomas Edison
12. Road building – 1836	John Loudon Mc Adam
13. Photography – 1839	George Eastman
14. Telegraph – 1837	Samuel F B Morse
15. First electric lamp – 1809	Humphy Dally

Question 9.
Read the para under the title “The workers” of Page No. 192 and comment on it.

The Workers : A survey in 1842 revealed that the average lifespan of workers was lower than that of any other social group in cities: it was 15 years Birmingham, 17 in Manchester, 21 in Derby. More people died, and died at a younger age, in the new industrial cities, than in the villages they had come from. Half the childern failed to survive beyond the age of five. The increase in the population of cities was because of immigrants, rather than by an increase in the number of childern born to families who already lived there. Deaths were primarily caused by epidemics of disease that sprang from the pollution of water, like cholera and typhoid, or of the air, like tuberculosis. More than 31,000 people died from an outbreak of cholera in 1832. Until late in the nineteenth century, municipal authorities were negligent in attending to these dangerous of life. The medical knowledge to understand and cure these diseases was unknown.

(OR)

A survey in 1842 revealed that the average lifespan of workers was lower than of any other social group in cities

Q: “What were the problem faced by workers in those days”. Comment it.
Answer:

• The life of the workers was hard.
• Multiple families were living in one apartment.
• Very poor sanitary conditions in the factories and in houses.
• Not enough earning to buy basic needs.
• Poor living standards.
• The short span of lives.
• Lack of medical facilities.
• Epidemic diseases.
  It was miserable to lead life.

Question 10.
Mention the consequences of the Industrial Revolution in the Economic field. Write a report and present in your class.
Answer:
Some 20th century historians argued that the process of economic change took place gradually.

1. GDP, per capita income was broadly stable before the industrial revolution and the emergence of the modern capitalist economy.
2. The Industrial Revolution began an era of per capita economic growth in capitalist economies.
3. Economic historians are in agreement that the onset of the industrial revolution is the most important event in the history of humanity.
4. Rapid increase in technology which affects production.
5. Standardisation of production process and parts.
6. Substantially lower transportation costs and development of improved transportation systems.
7. Better and cheaper intermediate good production and
8. Vast increase in global trade.

9th Class Social Studies 15th Lesson Industrialisation and Social Change InText Questions and Answers

Question 1.
Write two important inventions which revolutionised the textile industry. (Text Book Page No. 188)
Answer:

1. Water powered loom – Edmund Cartwright.
2. Spinning Jenney – James Hargreaves.

Question 2.
Mention two important industrialisation effects on women and children’s life. (Text Book Page No. 193)
Answer:

• Women lost their family life and children their childhood.
• Women had gained increased financial independence and self-esteem. Children worked in factories and stayed away from education.

Question 3.
Compare the industrialisation in Germany and France. Identify similarities and differences. (Text Book Page No. 195)
Answer:
Similarities :

• Germany and France lacked colonial resources.
• In both the countries industrialisation received a boost by the introduction of.railways in 1830s.
• Railways stimulated trade, communication and economic growth.

Differences :

Germany	France
1) German industrialisation was greatly facilitated by the German government.	1) France, in contrast, was slow in industrialising.
2) The needed heavy capital investment was received from large banks.	2) France did not develop banks which could mobilise large amount of capital and lend them to industrialists.
3) Market facilities were provided on large scale.	3) Market facilities were provided after 1860.
4) Germany gained back her coal mines.	4) France lost her coal mines to Germany.
5) The industrial units were very large.	5) The units were run at homes only.

Question 4.
Discuss the developments in Britain and in other parts of the world in 18th entury that encouraged British Industrialisation. (Text Book Page No. 187)
Answer:

• The Industrial Revolution took place in Great Britain almost a century before any other country.
• At that time Great Britain was a very powerful country that controlled many colonies.
• The country gained abundant useful resources from these colonies that aided its growth.
• The country had also just experienced an Agriculture Revolution.
• The country could support the demand for workers in factories. It has many natural resources.
• During the Industrial Revolution, the government of Britain was stable, wealthy and supportive of economy growth. So the Industrial Revolution was emerged first in Great Britain.
• The Industrial Revolution on continental Europe came a little later than in Great Britain, this involved the application of technology developed in Great Britain in new places. Often the technology was purchased from Britain or British engineers and entrepreneurs moved in search of new opportunities.
• The German, Russian and Belgian governments also provided state funding to the new industries.
• France’s economic growth industrialisation process was slow and steady along the 18^th and 19^th centuries.
• U.S. also supported Industrial Revolution and provided fuels for economic and industrial growth.
• Japan : There Industrial Revolution began about 1870 as Meiji period leaders decided to catch up with the west.

Question 5.
Discuss the effects of early industrialisation on British towns and villagesandcompare these with similar situation in India. (Text Book Page No. 194)
Answer:
New technology and techniques in agriculture paved the way for change. As surplus of cheap agriculture labour led to serve unemployment and rising poverty in many rural areas. As a result, many people left the countryside to find work in towns and cities. So the scene was set for a large scale labour intensive factory system. It led to urbanization.

In India during colonial rule, the British exported all the raw material to Britain. They did not establish or develop any industry here. They did not encourage the agriculture. They imported the finished goods. Both the agriculture and cottage industries were disturbed. As the agriculture is the backbone of India, the dependants suffered a lot. The dependants on agriculture became cheap labour.

Question 6.
What factors enabled Germany to outstrip England and France in industrialisation? (Text Book Page No. 195)
Answer:
The factors that enabled Germany to outstrip England and France in industrialisation:

1. Its government assistance.
2. Transport facilities.
3. The governments’s control over working class, movement with a heavy hand.
4. The government provided for many social benefits and insurance for the workers.
5. Benefit from the technical developments achieved by Britain and U.S.A.
6. Heavy capital investment facilities from large banks.
7. A great proportion of Germany’s industrial production was used to build up Germany’s military and naval power.

Question 7.
Why is high quality steel and iron necessary for industrialisation? Discuss in the class. (Text Book Page No. 188)
Answer:
Throughout the 18 and 19 centuries the English steel and iron makers produced blister and crucible steel and iron. In the 18th century innovations like steam boats, rail road and guns increased the demand for fine iron and steel.

Question 8.
Why do you think the mining of iron ore and coal received equal importance? (Text Book Page No. 188)
Answer:
I think coal is used for smelting iron. So the mining of iron ore and coal received equal importance.

Question 9.
Why do you think the early industrial centres were situated near the iron and coal mines? (Text Book Page No. 188)
Answer:
I think there were no proper transportation facilities to transport the coal and iron. And it is very difficult also to transport such heavy things from one place to another place. Later the canal and rail road transports were introduced and developed. So the early industrial centres were situated near the iron and coal mines.

Question 10.
Why do you think France lagged behind in industrial development? (Text Book Page No. 195)
Answer:
France was slow in industrialising. Even by the end of 19^th century she remained a rural country with a large majority of people cultivating small plots of land. Manufacturers found it more profitable to give out work to rural workers who worked at home rather than to set up factories in towns. Such rural domestic production began to decline after 1850 resulting in economic adversity for the people. Machines in towns began to take over much of the work and only delicate hand work was given out to rural workers. Much of French industrialisation was a result of the spread of railway and road networks after 1860 which created a wide market for its industrial goods.

France also did not develop Banks which could mobilise large amount of capital and lend them to industrialists. As a result most of French manufacturers depended upon family resources. They remained small companies as a result. It also made them slow in adopting new ideas and technologies.

Heavy industry based on iron and coal was slow to develop in France as she did not have good reserves of coal and depended upon expensive imports. Thus French industrialisation remained focused on consumer products like textiles, which were basically small scale enterprises. This was in contrast to the German and British Industrial situation where heavy industries predominated.

So France lagged behind industrial development.

Question 11.
What were the difficulties faced by women and children during industrial revolution? (Text Book Page No. 186)
(OR)
What are the difficulties faced by Women and Children during industrial revolution? What is your reaction towards this?
Answer:
The following selections are testimonies from England and Wales collected by Parliamentary Commission who began to investigate the industrial employment of women and children in the early 1840s.

1. Working conditions were unsanitary and the work was dangerous.
2. Education of the children suffered because of the demands of work.
3. Home life suffered as women were faced with the double burden of factory work formed by domestic chores and child care.
4. Men assumed supervisory roles over women and received higher wages.
5. Unsupervised young women away from home generated societal fears over their fate.
6. As a result of the need for wages in the growing cash economy, families became dependent on the wages of women and children.
7. There was some worker opposition to propagate that child and female labour should be abolished from certain jobs.
8. Children as young as 5 years old worked hard hours for little or no pay (sometimes 19 hours a day)
9. Large, heavy and dangerous equipment was very common for children to be using or working near.
10. Many accidents occurred injuring or killing children on the job.

My reaction :
This is very cruel and inhuman treatment. If it is there now-a-days the factory owners should be punished by govt severely.

Andhra Pradesh SCERT AP State Board Syllabus 8th Class Physical Science Physics Chapter Wise Important Questions and Answers in English Medium and Telugu Medium are part of AP Board 8th Class Textbook Solutions.

Students can also read AP Board 8th Class Physical Science Solutions (Physics & Chemistry) for exam preparation.

AP State Syllabus 8th Class Physical Science Important Questions and Answers English & Telugu Medium

AP 8th Class Physical Science Important Questions and Answers in English Medium

• Chapter 1 Force Important Questions
• Chapter 2 Friction Important Questions
• Chapter 3 Matter Around Us Important Questions
• Chapter 4 Synthetic Fibres and Plastics Important Questions
• Chapter 5 Metals and Non-Metals Important Questions
• Chapter 6 Sound Important Questions
• Chapter 7 Coal and Petroleum Important Questions
• Chapter 8 Combustion, Fuels and Flame Important Questions
• Chapter 9 Electrical Conductivity of Liquids Important Questions
• Chapter 10 Reflection of Light at Plane Surfaces Important Questions
• Chapter 11 Some Natural Phenomena Important Questions
• Chapter 12 Stars and the Solar System Important Questions

AP 8th Class Physics Important Questions and Answers in Telugu Medium

• Chapter 1 బలం Important Questions
• Chapter 2 ఘర్షణ Important Questions
• Chapter 3 మన చుట్టూ ఉన్న పదార్థం Important Questions
• Chapter 4 కృత్రిమ దారాలు మరియు ప్లాస్టిక్లు Important Questions
• Chapter 5 లోహాలు మరియు అలోహాలు Important Questions
• Chapter 6 ధ్వని Important Questions
• Chapter 7 నేలబొగ్గు మరియు పెట్రోలియమ్ Important Questions
• Chapter 8 దహనం, ఇంధనాలు మరియు మంట Important Questions
• Chapter 9 ద్రవాల విద్యుత్ వాహకత Important Questions
• Chapter 10 సమతలాల వద్ద కాంతి పరావర్తనం Important Questions
• Chapter 11 కొన్ని సహజ దృగ్విషయాలు Important Questions
• Chapter 12 నక్షత్రాలు – సౌరకుటుంబం Important Questions

AP State Syllabus AP Board 9th Class Physical Science Important Questions Chapter 2 Laws of Motion

AP State Syllabus 9th Class Physical Science Important Questions 2nd Lesson Laws of Motion

9th Class Physical Science 2nd Lesson Laws of Motion 1 Mark Important Questions and Answers

Question 1.
Calculate the momentum of a fast moving ball with a velocity 2.2 m/s of mass 6 kg.
Answer:
mass (m) = 6 kg
velocity (v) = 2.2 m/s
momentum = mv = 6 × 2.2 = 13.2 kg.m.s^-1
The momentum of a fast moving ball is 13.2 kg ms^-1.

Question 2.
What is Newton’s first law of motion?
Answer:
Every object will remains at rest or in a state of uniform motion, unless compelled to change its state by the action of a net force.

Question 3.
From a fixed height, two eggs are dropped such that one falls on a concrete floor and the other on a cushioned pillow. The egg falling on the concrete floor breaks and the one falling on the pillow does not break. Explain why in terms of momentum.
Answer:

• The change of momentum of an egg takes place in shorter time in case of concrete surface.
• The change of momentum of the egg takes place in longer time in case of cushioned pillow.
• Hence, egg does not break on cushioned pillow.

9th Class Physical Science 2nd Lesson Laws of Motion 2 Marks Important Questions and Answers

Question 1.
A vehicle of mass 300 kg travels at a velocity of 90 km/h. Find its momentum.
Answer:
Mass of the vehicle (m) = 300 kg
Velocity of the vehicle (v) = 90 km/h = 90 × \(\frac{5}{18}\) m/s = 25 m/s
Momentum = mv = 300 × 25 = 7500 kg.m.s^-1

Question 2.
“With our day to day experience, we must exert some force on an object to keep it moving”.
i) By which law, you can support the above lines?
ii) Which act on the body ? Either force or net force?
Answer:
i) Newtons first law of motion.
ii) Net force. The position of object is changed due to net force only.

9th Class Physical Science 2nd Lesson Laws of Motion 4 Marks Important Questions and Answers

Question 1.
Fill the following table.

Answer:

Question 2.
What is impulse? Derive the formula for impulse.
Answer:
Impulse :
The change of momentum of an object is called impulse.
Formulae for impulse ⇒ ∆p = F_net∆t.

Derivation :
We can express the second law of motion as

From the above equation we know that the product of net force and interaction time is called impulse of net force (∆p).

Question 3.
State and prove the law of conservation of linear momentum.
Answer:
Law of conservation of momentum : Law of conservation of momentum states, in the absence of a net external force on the system, the momentum of the system remains unchanged.
Explanation :

• Let two marbles with masses nij and m2 travel with different velocities ut and u2 in the same direction along a straight line.
• If u₁ > u₂, they collide each other and the collision lasts for time’t’.
• During collision, each marble exerts force on other marble. [F₁₂ and F₂₁]
• Let v₁ and v₂ be the velocities of the marbles after collision.

Now look at the table.

• The total momentum before collision is equal to total momentum after collision.
• Hence, the total momentum remains unchanged before and after collision.

Question 4.
a) Name the ‘machine’ use to prove Newton’s laws of motion. Draw a neat diagram of it.
(OR)
The masses ‘m ‘ and ‘m2’ are attached to a string and roll over a pully, which is attached to a rigid support. Identify the machine and draw the neat diagram of it.
Answer:
a) Atwood machine.
Answer:

b) Draw FBD of both, masses on it.
Answer:

9th Class Physical Science 2nd Lesson Laws of Motion 1 Mark Important Questions and Answers

Question 1.
Newton’s first law of motion is also called
Answer:
Law of inertia.

Question 2.
State Newton’s second law of motion.
Answer:
The rate of change of momentum of a body directly proportional to the net force acting on it and it takes place in the direction of net force.

Question 3.
What is inertia?
Answer:
The natural tendency of objects to resist a change in their state of rest or of uniform motion is called inertia.

Question 4.
What is momentum?
Answer:
Linear momentum of a body is the product of its mass and velocity.
Momentum (p) = mass (m) × velocity (v)

Question 5.
State Newton’s third law of motion.
Answer:
When an object exerts a force on the other object, the second object exerts a force on the first one with equal magnitude and in opposite direction.

Question 6.
Write the law of conservation of momentum.
ANswer:
The law of conservation of momentum states that in the absence of net external force on the system, the momentum of the system remains unchanged.
m₁u₁ + m₂u₂ = m₁v₁ + m₂v₂

Question 7.
What is an impulse?
Answer:
The product of net force and interaction time of a system is called impulse of net force.
Impulse ∆p = F_net. ∆t.

Question 8.
What is the Aristotle’s conclusion about the natural state of an object?
Answer:
Aristotle concluded that the natural state of an earthly object is to be at rest. Hence the object at rest requires no explanation as any moving object naturally comes to rest.

Question 9.
What is the Galileo’s conclusion on the motion of an object?
Answer:
Galileo gave birth to modern science by stating that an object in motion will remain in same motion as long as no external force is applied on it.

Question 10.
What is the effect of mass on inertia?
Answer:
As mass increases, inertia increases.
Mass is a property of an object that specifies how much inertia the object has.

Question 11.
Who proposed laws of motion?
Answer:
Sir Isaac Newton proposed the laws of motion.

Question 12.
Give two daily life examples where you experience inertia.
Answer:

• When the bus which is at rest begins to move suddenly, the person standing in the bus falls backward.
• When you are travelling in a bus the sudden stop of the bus makes you fall forward.

Question 13.
If action is always equal to the reaction, explain how a horse can pull a cart.
Answer:
Horse and cart constitutes a single system. So they cannot form action-reaction pair. Therefore, horse can pull the cart.

9th Class Physical Science 2nd Lesson Laws of Motion 2 Marks Important Questions and Answers

Question 1.
What is momentum? What are its units in S.I. system?
Answer:
Momentum (p) of a body is defined as the product of its mass (m) and velocity (v).
Momentum (p) = mass (m) × velocity (v)
p = mv
S.I. units of momentum are kg. m /sec (or) N – sec.

Question 2.
A mass of 0.5 kg has been suspended to a roof as shown in the figure. What is the force exerted by the rope on the object?

Answer:
The forces acting on the object of mass 0.5 kg are
i) gravitational force (downward) = 0.5 x 9.8 = 4.9 N
ii) Tension in the string T (upward).
The object is at rest. Hence the two forces are equal.
∴ The force exerted by the string on the object is 4.9 N (upwards).

Question 3.
Write few incidents if there were no friction.
(OR)
What happens when there were no friction in this world?
Answer:
If there were no friction,

1. we could not be able to walk on ground.
2. we would not be able to stop a fast moving car.
3. any object could not be able to stay on the ground.

Question 4.
What are the factors influencing acceleration? Explain.
Answer:
Factors influencing acceleration are force and mass.
Force :
As the net force increases, the acceleration increases when mass remains constant.

Mass :
When force is constant, as the mass increases, the acceleration decreases.

Question 5.
Why does a fielder catch a fast moving cricket ball by pulling back his arms while catching it?
(OR)
Why does a cricketer move his hands backwards while catching a fast moving cricket ball?
Answer:

• When he pulls back his arms he experiences a smaller force for a longer time.
• The ball stops only when your arms stop.
• This is to avoid a large impulse.
• If he doesn’t pull his arms back, the ball will hurt him.
• This is due to a larger force for a smaller time.

Question 6.
What is the state of an object when no net force is acting on an object?
Answer:
If the net force acting on an object is zero, the object which is at rest remains at rest or if the object is already moving with a certain velocity it continue to move with same velocity.

Question 7.
Which of the following has more inertia?
a) A rubber ball and a stone of the same size.
b) A bicycle and a train.
c) A five rupees coin and a one-rupee coin.
Answer:
As the mass of the object increases the inertia of the object increases.
a) Stone has more mass than rubber ball. So stone has more inertia.
b) Train has more inertia.
c) 5 rupee coin has more inertia.

Question 8.
Explain why some of the leaves may get detached from a tree, if we vigorously shake its branch?
Answer:
The leaves are at the state of rest. When the tree is vigorously shaken the state of rest is disturbed. So the leaves are detached from the tree due to inertia of rest.

Question 9.
Which would require a greater force – accelerating a 2 kg mass at 5 ms^-2 or a 4 kg mass at 2 ms^-2?
Answer:
Force F = ma
Here we have m₁ = 2kg, a₁ = 5 ms^-2 and m₂ = 4 kg, a₂ = 2ms^-2.
Thus F₁ = m₁a₁
Thus accelerating a 2 kg mass at 5 ms^-2 would require a greater force.

Question 10.
A motor car is moving with a velocity of 108 km/h and it takes 4s to stop after the brakes are applied. Calculate the force exerted by the brakes on the motor car if its mass along with the passengers is 1000 Kg.
Answer:

Question 11.
Explain why is it difficult for a fireman to hold a hose, which ejects large amounts of water at a high velocity.
AnswerL
It is difficult for a fireman to hold a hose which ejects large amounts of water at a high velocity because due to high velocity of water the hose moves backward directiondue to Newton’s third law.

Question 12.
From a rifle of mass 4 kg, a bullet of mass 50 g is fired with an initial velocity of 35 ms^-1. Calculate the initial recoil velocity of the rifle.
Answer:
Mass of rifle m₁ = 4 kg
Mass of bullet m₂ = 50 g = \(\frac{50}{1000}\) = 0.05 kg
Initial velocity of rifle u₁ = 0
Initial velocity of bullet u₂ = 0
Final velocity of rifle (recoil velocity) v₁ = v
Final velocity of bullet v₂ = 35 ms^-1
According to law of conservation of momentum
m₁u₁ + m₂u₂ = m₁v₁ + m₂v₂.
4(0) + 0.05 (0) = 4v + 0.05 × 35
4v = – 1.75
v = – 0.44 m/s

Question 13.
An automobile vehicle has a mass of 1500 kg. What must the force between the vehicle and road if the vehicle is to be stopped with a negative acceleration of 1.7 ms^-2?
Answer:
m = 1500 kg ;
a = – 1.7 ms^-2
F = ma = 1500 ×- 1.7 = -2550 N
Negative sign indicates that it is a retarding force.

Question 14.
What happens to a person standing in a bus when the bus which is at rest begins to move suddenly?
(OR)
Explain static inertia with an example.
Answer:

• The property of an object at rest will try to remain at rest is called “static inertia”.
• For example, when the bus which is at rest begins to move suddenly, the person standing in the bus falls backward because of static inertia of the body.
• Bus pulls the legs forward while body is in the rest position (static inertia).

Question 15.
Observe the given figure.
a) What happens to the coin, when we pull the paper with a jerk of force?
b) Why?
Answer:

1. The coin falls inside the glass.
2. This is due to static inertia of the coin.
3. This means coin in the state of ‘rest’ before and after pulling the paper. It falls down due to gravity only.

9th Class Physical Science 2nd Lesson Laws of Motion 4 Marks Important Questions and Answers

Question 1.
Give some examples for Newton’s third law of motion from your day-to-day observations.
Answer:
1) Flying of birds :
a) When birds fly, they push the air downward with their wings.
b) The air pushes back the bird in opposite upward direction.
c) These two forces are equal in magnitude and opposite in direction. Hence the bird can fly.

2) Swimming of fish :
a) When a fish swims in water, it pushes back the water.
b) The water pushes the fish with equal but in opposite direction.
c) Hence the fish moves forward.

3) Launching of a rocket:
a) A rocket accelerates by expelling gas at high velocity.
b) The reaction force of the gas on the rocket accelerates the rocket in a direction opposite to the expelled gases.

Question 2.
Derive F = ma.
Answer:
1) Newton’s second law of motion states that the rate of change of momentum of an object is proportional to the net force applied on the object in the direction of net force.

Question 3.
How did Galileo differ the statement of Aristotle ‘The natural state of an earthy object is to be at rest?
(OR)
Write the great experiments of Galileo on inclined planes.
(OR)
How do you appreciate Galileo, the father of modern science?
Answer:

• Galileo came up with two ingenious thought experiments.
• He did his experiments on inclined planes with smooth surfaces.
• He observed that the smoother the surface the farther the ball travelled.
• He extended this ajgument and concluded that if the surface was perfectly smooth, the ball will travel indefinitely until encountered by another object.

• As shown in the figure 1 (a) he observed that when a marble rolls down a slope it picks up speed due to the force of gravity of the earth.
• As shown in the figure 1(b) when the object rolls up an inclined plane, its speed decreases.
• Now let us assume that a marble is moving on a level surface as shown in the figure 1(C), it has no reason to speed up or slow down.
• So, it will continue to move with constant velocity.
• By this experiment, Galileo came to a conclusion which was in contrast to Aristotle’s belief that the state of an earthy object is to be at rest.

Question 4.
Explain Newton’s third Law of motion with an activity.
(OR)
Take two spring balances of equal calibrations. Connect the two spring balances and pull them in opposite direction. Does they show different readings? Why?
Answer:
Newton’s third law of motion : When an object exerts a force on an other object, the second object also exerts a force on the first one which is equal in magnitude but opposite in direction.

Activity:

1. Let us take two spring balances of equal calibrations.
2. Connect the two springs balances as shown in the figure.
3. Pull the balances in opposite direction.
4. Observation : Spring balances shows same readings.
5. Here, one spring balance shows reading of ‘action’ force, and other spring balance shows reading of ‘reaction’ force.
6. Forces are equal, direction are opposite.
7. This shows Newton’s third law of motion.

Question 5.
Take two marbles of m₁, m₂ mass respectively. Make a collision in one second with marbles using u₁, u₂ initial velocities respectively. Take the final velocities as v₁, v₂ You observed the following in the experiment.
m₁ = 10 kg u₁ = 5 m/s v₁ = 15 m/s
m₂ = 100 kg u₂ = 2 m/s -v₂ = 1 m/s
t = 1 sec
Fill the table with suitable answers and write the conclusion from it.

Answer:

Conclusion :

1. The table momentum is unchanged before and after collision.
2. We can say that the momentum is conserved.

Question 6.
How do you appreciate ‘Laws of motion’.
(OR)
How do you appreciate Newton, the great scientist.
Answer:

1. Built upon ideas primarily developed by Aristotle and Galileo, Sir Isaac Newton proposed his three fundamental Laws.
2. These Laws explain the connection between force and a change in motion.
3. These Laws are popularly known as Newton’s Law of motion.
4. Newton’s first law of motion : A body continuous its state of rest or of uniform motion unless a net force acts on it.
5. This law is very useful to study about inertia, mass, weight of an object.
6. This law is used to prepare cranes, machines, vehicles, etc.
7. Newton’s second Law of motion : The rate of change of memontum of a body is directly proportional to the net force acting on it and it takes place in the direction of net force.
8. This law is useful to find the attraction between two objects.
9. It is very useful to study the behaviour of substances like velocity, acceleration, force, momentum, etc.
10. Newton third law of motion : If an object exerts a force on an other object, the second object also exerts a force on the first one which is equal magnitude but opposite in direction.
11. This law is used to prepare rockets.
12. In this way Newtons Law’s are very useful in the fields of automobiles space centres and various industries.
13. In this way Newton laws changed the life of human beings.
14. So, I am appreciating the laws of motion and Newton for his great service to us.

Question 7.
Write suitable law and concept to the given situation or vice versa in the given table.

Answer:
A = Newton’s first law of motion
B = Static inertia
C = Newton’s third law of motion
D = Force of action = force of reaction
E = Newton’s second law of motion
F = Less impulse of net force
G = Newton’s third law of motion
H = Force of action = force of reaction
I = Fish swims in water
J = Force of action = force of reaction
K = Dropping egg on a cushion
L = Object thrown in universe (No external forces acts)
M = Newton’s first Law of motion
N = Bullet hurts
O = Newton’s second law of motion
P = Less impulse of net force
Q = Newton’s Second law of motion
R = Less momentum

SCERT AP Board 9th Class Social Solutions 20th Lesson Democracy: An Evolving Idea Textbook Questions and Answers.

AP State Syllabus 9th Class Social Studies Solutions 20th Democracy: An Evolving Idea

9th Class Social Studies 20th Lesson Democracy: An Evolving Idea Textbook Questions and Answers

Improve Your Learning

Question 1.
How does democracy produce an accountable, responsive, and legitimate government?
Answer:
1. Accountable :
Democracy produces a government which is accountable to all people, it is the basic outcome of democracy. It will produce a government which responds to people.

2. Legitimate :
In democracy, elections are conducted through which people select their representatives. If they do not react for their demands, they choose another representative in the next elections.

3. Responsive :
Democracy produces a government which responds to all the demands and needs of different people.

Question 2.
What are the conditions under which democracies accommodate social diversity?
Answer:

• In every society, there are people belonging to different religions, income groups, and using different languages.
• Democracy means that equal treatment is given to all the individual and that there should not be any discrimination on the basis of caste, gender, race, religion, or region.
• It accommodates all the social diversity by giving equal rights and freedoms to the people.
• In a democratic set up, people from socially weaker sections of the society are allowed to vote and choose their representatives in the government, and no particular religion or language is given any special preference.
• Also, women are given equal rights as men in the society.
• It also ensured that the rule of the majority is not by those who are in majority just in number. The majority group needs to work in harmony with the minority group such that interests and concerns of every group are respected.

Question 3.
Give arguments to support or oppose the following assertions :
A) Industrialised countries can afford democracy but poor countries need dictatorship to become rich.
Answer:
No, we do not agree with the statement, because the nature and scope of democracy is not confined or limited to rich or industrialised countries only. Democracy is the government of modern era which provides accountable, representative, responsible and legitimate government to the people. It also tries to accommodate social differences and promote economic growth which a dictatorship cannot. Hence, a poor country can also afford democracy for popular government and economic growth.

B) Democracy can’t reduce inequality of incomes between different citizens.
Answer:
We do not agree with the statement. Democracy can’t reduce inequality of incomes between different citizens. But democracy can reduce the economic inequality by providing equal distribution of wealth and equal opportunities to all.

C) Government in poor countries should spend less on poverty reduction, health, education, and spend more on industries and infrastructure.
Answer:
We do not agree with this statement. Poverty is one of the social challenges which democracy has to accommodate, so poor countries should spend more to check poverty.

Besides food, clothing, health and education are the basic needs of the people and it is the duty of the government to provide these facilities to the people.

D) In democracy, all citizens have one vote, which means that there is absence of any domination and conflict.
Answer:
Yes, we do agree with the statement. Democracy stands for political equality and guarantees Universal Adult Franschise. Universal Adult Franchise gives right to vote to every adult citizen of the country. Hence there is no chance of political domination and conflict.

Question 4.
In the context of assessing democracy, which among the following is odd one out? Democracies need to ensure :
A) free and fair elections
B) dignity of the individual
C) majority rule
D) equal treatment before law
Answer:
(C) Reason : Majority rule is odd one out because democracy ensures people’s rule based on popular consensus.

Question 5.
Studies on political and social inequalities in democracy show that:
A) democracy and development go together.
B) inequalities exist in democracies.
C) inequalities do not exist under dictatorship.
D) dictatorship is better than democracy.
Answer:
(B) Inequalities exist in democracies

Question 6.
Here is some information about six countries. Based on this information, how would you classify each of these countries? Write ‘democratic’, ‘undemocratic’ or ‘not sure’ against each of these.
i) Country A : People who do not accept the country’s official religion do not have a right to vote
ii) Country B : The same party has been winning elections for the last twenty years
iii) Country C : Ruling party has lost in the last elections
iv) Country D : The parliament cannot pass a law about the army without the consent of the Chief of Army
v) Country E : The parliament cannot pass a law reducing the powers of the judiciary
vi) Country F : All the major economic decisions about the country are taken by officials of the central bank which the ministers cannot change,
Answer:

i) Undemocratic
ii) Not sure (More details are needed)
iii) Democratic
iv) Undemocratic
v) Democratic
vi) Undemocratic

Question 7.
Each of these statements contains a democratic and an undemocratic element. Write out the two separately for each statement.
A) A minister said that some laws have to be passed by the parliament in order to confirm to the regulations decided by the World Trade Organisation.
Answer:
Passing laws by the parliament is democratic whereas passing it in confirmity to the regulations decided by WTO is undemocratic.

B) The Election Commission ordered re-polling in a constituency where large scale rigging was reported.
Answer:
To order repoll in a constituency by the Election Commission is democratic whereas rigging is undemocratic.

C) Women’s representation in the parliament has never reached 10 per cent. This led women’s organisations to demand one-third seats for women.
Answer:
Demand by women’s organisation to reserve 1/3 seats for women is democratic whereas less 10% women’s representation in the parliament is undemocratic.

Question 8.
Write a response to the following arguments against democracy :
A) Army is the most disciplined and corruption-free organisation in the country. Therefore army should rule the country.
Answer:
Army rule is always undemocratic. Under this system, people do not enjoy freedom of speech and expression and are not allowed to criticise the government. Military rule is another name for dictatorship. Moreover, many army men are not disciplined and are corrupt.

B) Rule of the majority means the rule of ignorant people. What we need is the rule of the wise, even if they are in small numbers.
Answer:
Rule of majority is democratic as it represents the views of all sections of the people.

C) If we want religious leaders to guide us in spiritual matters, why not invite them to guide us in politics as well. The country should be ruled by religious leaders.
Answer:
Rule by religious leaders is not democractic. It arouses communal feeling among the people which sometimes lead to communal riots. Besides many religious leaders do not have any experience of administration.

Question 9.
Locate the following countries in the world map.
1. Sri Lanka
2. Belgium
3. Russia
4. America (USA)
Answer:

Question 10.
Read the first two paragraphs under the subheading ‘Dignity and freedom of the citizens’ and answer the following question.

Democracy stands much superior to any other form of government in promoting dignity and freedom of the individual. Every individual wants to receive respect from fellow beings. Often conflicts arise among individuals because some feel that they are not treated with due respect. The passion for respect and freedom are the basis of democracy. Democracies throughout the world have recognised this, at least in principle. This has been achieved in various degrees in various democracies. For societies which have been built for long on the basis of subordination and domination, it is not a simple matter to recognise that all individuals are equal.

Take the case of dignity of women. Most societies across the world were historically male-dominated societies. Long struggles by women have created some sensitivity today that respect to and equal treatment of women are necessary ingredients of a democratic society. That does not mean that women are actually always treated with respect. But once the principle is recognised, it becomes easier for women to wage a struggle against what is now unacceptable legally and morally. In a non-democratic set up, this unacceptability would not have legal basis because the principle of individual freedom . and dignity would not have the legal and moral force there. The same is true of caste inequalities. Democracy in India has strengthened the claims of the disadvantaged and discriminated castes for equal status and equal opportunity. There are instances still of caste-based inequalities and atrocities, but these lack the moral and legal foundations. Perhaps it is this recognition that makes ordinary citizens value their democratic rights.

Write about the dignity and freedom of the citizens in a democratic country in your own words.
Answer:

• In a democratic country people have freedom to choose their representatives on the basis of universal adult franchise.
• Most societies across the world are male dominated. Equal treatment of women became the necessary requirement of a democratic society. Thus their status in democratic countries improved.
• In a non-democratic set up, there is no legal basis for freedom and dignity of individuals.
• Democracy in India has strengthened the claims of the disadvantaged and discriminated castes for equal status and equal opportunity.
• Democracy transforms people from the status of subjects under a king or a dictator to the status of citizens with rights and duties.
• Many fundamental rights are granted to citizens in a democratic country. One such right is to travel anywhere, freedom to any profession, to choose any religion, etc.

Question 11.
What are the reasons for the people to fight for democracy?
Answer:
Reasons:

1. A democracy is the best form of government.
2. Democracy promotes equality.
3. It promotes dignity and freedom of the individual.
4. It improves the quality of decision making.
5. People can elect the leaders of their choice.
6. People have the right to get the information about the public administration.

Question 12.
Give some examples which prove that democracy is practised in our schools.
Answer:

1. Admissions to the students without any differences of caste/creed / religion.
2. Elections to elect SPL / CPL
3. Parents, teachers, associations
4. Social clubs
5. Community participation
6. Equality in teaching etc.

Question 13.
Conduct elections in your class to elect class representative with the help of your teacher.
Answer:
Note : ‘Mock poll’ should be conducted in the class with the help of the teacher.

9th Class Social Studies 20th Lesson Democracy: An Evolving Idea InText Questions and Answers

Question 1.
Discuss the solutions given in both the countries to accomodate social, religious, and linguistics diversity in them. (Text Book Page No. 254)
Answer:
Both are democracies. Yet, they dealt with the question of power sharing differently. In Belgium, the leaders have realised that the unity of the country is possible only by respecting the feelings and interests of different communities and regions. Such a realisation resulted in mutually acceptable arrangements for sharing power. Sri Lanka shows us a contrasting example. It shows us that if a majority community wants to force its dominance over others and refuses to share power, it can undermine the unity of the country and force the country back several hundred years with internal conflicts and civil wars.

Question 2.
How will this chess board change? (Text Book Page No. 247)

Answer:
If the inequalities are vanished, the chess board will change.

Question 3.
If a party is repeatedly voted to power, does it mean that people really want it to come to power, or that there is no alternative or that people are not allowed to vote for any alternative? Answer on the basis of the following three case studies: (Text Book Page No. 249)
a. Since its independence in 1930, Mexico holds elections after every six years to elect its President. The country has never been under a military or dictator’s rule.But, until 2000, every election was won by a party called PRI (Institutional Revolutionary Party). Opposition parties did contest elections, but never managed to win. The PRI was known to use many unfair means to win elections. Teachers of government schools used to force parents to vote for the PRI.

b. Zimbabwe attained independence from White minority rule in 1980. Since then, the country has been ruled by ZANU-PF, the party that led the freedom struggle.Its leader, Robert Mugabe, has been ruling the country since independence. Elections have been held regularly and always won by ZANU-PF. President Mugabe is popular but also uses unfair practices in elections. His government has changed the Constitution several times to increase the powers of the President and make him less accountable. Opposition party workers are harassed and their meetings disrupted. There is a law that limits the right to criticise the President. Television and radio are controlled by the government and give only the ruling party’s version.

c. In China, elections are regularly held after every five years for electing the country’s parliament, called Quanguo Renmin Daibiao Oahui (National People’s Congress). The National People’s Congress has the power to appoint the President of the country. It has nearly 3,000 members elected from all over China. Some members are elected by the army. Before contesting elections, a candidate needs the approval of the Chinese Communist Party. Only those who are members of the Chinese Communist Party or eight smaller parties allied to it were allowed to contest elections held in 2002-03. The government is always formed by the Communist Party.
Answer:

1. Democracy requires free and fair elections.
2. People should have choice to vote.
3. People should not be forced by the government.
4. Electoral rolls should maintained in a right way.

In these 3 cases, these conditions are not fulfilled. So we can say that the elections are conducted in an undemocratic way.

Question 4.
Let us take the example of an election in India. Of all the residents in a region, let us assume that 1000 have right to vote. In any typical election about 60% people go to cast their votes. Thus, we have 600 people voting in an election. Let us assume that there are ten candidates in the election and of these the winning candidate gets about 250 votes, the second candidate gets 200 votes and the other candidates between them get about 150 votes. We declare the one with 250 votes the winner. Does he or she really represent the views and interests of the residents of the locality? Actually, he or she only represents one fourth of the voters. Is this a fair democratic arrangement ? Can there be better ways of representing the people in decision making bodies? (Text Book Page No. 250)
Answer:
He or she really represents the views and interests of the majority people of the locality. This may not be a fair democratic arrangement.

This controversial new look at democracy in a multicultural society considers the ideas of political inclusion and exclusion and recommends ways to engage in democratic politics in a more inclusive way. Processes of debate and decision making often marginalize individuals and groups because the norms of political discussion are biased against some forces of expression. Inclusion and democracy broadens our understanding of democratic communication by reflecting on the positive political function. It reconstructs concepts of civil society and public sphere.

Question 5.
Do the millions of poor people really have any control over the functioning of the elected functionaries? (Text Book Page No. 246)
Answer:
In a democracy, every citizen has certain basic rights that anyone cannot take away from them. I think people are using this during the time of elections.

Question 6.
Does democracy mean rule by people or merely rule by elected persons? (Text Book Page No. 246)
Answer:
Literally, democracy means rule by people only. But in practice, it is rule by elected persons.

Question 7.
How can people really participate in government on a day to day basis? (Text Book Page No. 246)
Answer:
This is possible when all policies and laws are made after extensive public discussions, in which people participate and openly state their needs and views. It also requires that people be involved in effective implementation of the policies and laws – by forming independent citizens committees.

Question 8.
Why do people not want to participate in governance? Is it because of poor knowledge or lack of interest or a feeling that they don’t have a real say in things? (Text Book Page No. 247)
Answer:
The people remain apathetic and they lose their interest in politics. Fore.g. : whoever may be the elected representative, he tries to save his position and wealth, etc.
So they do not want to participate in governance.

Question 9.
Why do you think does such high level of inequality persist even where the countries are democratic and government works in the interest of all people? (Text Book Page No. 248)
Answer:
In many countries like the USA, most of the media are owned by very rich corporate houses or media barons. They effectively manipulate and influence public opinion by what they high light and what they black out. The rich and powerful also have immediate access to members of the legislature and the ministers, and are in a position to influence their policies and programmes.

On the other hand, the poor and illiterate people have no such access to the government circles. Thus the government of many of these countries follow policies which seem to be contradictory to the interests of the poor and in favour of the rich.

So the high level of inequality persists even where the countries are democratic and government works in the interest of all people.

Question 10.
Even today, most countries do not give voting powers to people who have migrated from other countries. Actually, millions of people across the world live without these democratic rights simply because the countries they live in treat them as illegal immigrants. This is the plight of South American immigrants in the US or Turkish immigrants in France or Germany. Such immigrants and refugees are found all over the world including India. Should they not be part of democratic governance? (Text Book Page No. 247)
Think of some reasons for your answer.
Answer:
Democracy is based on the fundamental principle of political equality and inclusiveness. In a democracy, each adult citizen must have one vote and each vote must have one value. So they should also be a part of democratic governance.

Question 11.
Many governments give people the civil liberties. But they keep a careful watch on the activities of the citizens by tapping their telephones and letters, spying on them etc. Do you think this is justified? (Text Book Page No. 248)
Answer:
Today the conditions in the world are so. All the countries are in the shadow of terrorism. So the governments are supposed to do like that. But the government should not disclose the secrecy of the individuals. Then only I think this is justified.

AP State Syllabus AP Board 9th Class Physical Science Solutions Chapter 10 Work and Energy Textbook Questions and Answers.

AP State Syllabus 9th Class Physical Science Solutions 10th Lesson Work and Energy

9th Class Physical Science 10th Lesson Work and Energy Textbook Questions and Answers

Improve Your Learning

Question 1.
Define work and write its units. (AS 1)
Answer:
Work : Work can be defined as the product of the force (F) and the distance (s) moved along the direction of the force.
Work done = Force × displacement = F × s
[This formula is used in only translatory motion of the object]

1. Work is a scalar quantity.
2. Unit of work is ‘N – m’ or ‘Joule’ (J).

Question 2.
Give few examples where displacement of an object is in the direction opposite to the force acting on the object. (AS 1)
Answer:

• When a ball is thrown up, the motion is in upward direction, whereas the force due to earth’s gravity is in downward direction.
• If a ball is moving on plain ground, will get stopped after sometime, due to frictional force acting on it in opposite direction.

Question 3.
Identify the wrong statement among the following. Rewrite them by making necessary corrections. (AS 1)
a) Work and energy have different units.
Answer:
Correction :
Work and energy have same units.

b) When an aeroplane takes off, the work done by its weight is positive.
Answr:
Correction : When an aeroplane takes off, the work done by its weight is negative.

c) The potential energy of spring increases when it is extended and decreases when it is compressed.
Answer:
Correct.

d) If the work done by external forces on a system is negative then the energy of the system decreases.
Answer:
Correct.

e) When a body is falling freely from a height, its kinetic energy remains constant.
Answer:
Correction : When a body is falling freely from a height, its K.E. increases and P.E. decreases, but the total energy of the body remains constant.

f) The unit of power is watt.
Answer:
Correct.

Question 4.
What is mechanical energy? (AS 1)
Answer:
The sum of the kinetic energy and the potential energy of an object is called its mechanical energy.

Question 5.
State the principle of conservation of energy. (AS 1)
Answer:
Energy can neither be created nor destroyed. It can only be changed from one form to another.

Question 6.
When you lift a box from the floor and put it on an almirah the potential energy of the box increases but there is no change in its kinetic energy. Is it violation of conservation of energy? Explain. (AS 7)
Answer:

• When the box is on the floor, it has no K.E., but has some P.E.
• Its P.E. increases as it is lifted and put on an almirah.
• In this event, the energy produced by the person converts into K.E. and the total M.E. remains same.
• Hence it is not the violation of conservation of energy.

Question 7.
One person says that potential energy of a particular book kept in an almirah is 20 J and other says it is 30 J. Is one of them necessarily wrong? Give reasons. (AS 2, AS 1)
Answer:
Two cases will arise in this situation.
Case – I :
One of them will be wrong, if both of them kept the book in the same shelf of the almirah.

Case – II :
Both of them will be correct, if the first person keeps the book in lower shelf and the second one keeps the book in upper shelf of the almirah.

Question 8.
In which of the following cases is the work done positive or zero or negative? (AS 1)
a) Work done by the porter on a suitcase in lifting it from the platform on to his head.
Answer:
Positive

b) Work done by the force of gravity on suitcase as the suitcase falls from porter’s head.
Answer:
Positive

c) Work done by the porter standing on platform with suitcase on his head.
Answer:
Zero

d) Work done by force of gravity on a ball thrown up vertically up into the sky.
Answer:
Negative

e) Work done by force applied by hands of a man swimming in a pond.
Answer:
Negative

Question 9.
What is potential energy? Derive an equation for gravitational potential energy of a body of mass ‘m’ at a height ‘h’. (AS 1)
Answer:
Potential energy:
The energy possessed by an object because of its position or shape is called its potential energy.

Potential energy of a body at height (Or) Gravitational potential energy :

1. The gravitational potential energy of an object at a point above the ground is defined as the work done in raising it from the ground to that point against gravity.
2. Consider an object of mass ‘m’ raised to height ’h’ from the ground.
3. A force is required to do this.
4. The minimum force required to raise the object is equal to the weight of the object (mg).
5. The object gains energy equal to the work done on it.
6. Let the work done on the object against gravity be ‘W’.
   ∴ W = Force × displacement
   = mg × h
   W = mgh
7. The object gains the energy equal to the mgh’ units.
8. This energy is the potential energy of the object at a height ‘h’.
   ∴ P.E. = mgh

Question 10.
When an apple falls from a tree what happens to its gravitational potential energy just as it reaches the ground? After it strikes the ground? (AS 7)
Answer:

• Let us imagine an apple of mass ‘m’ falls from a height h.
• Before starting to fall down, its velocity is zero. Hence its energy is purely potential.
• When it falls down, its gravitational potential energy gradually converts into kinetic energy, but the entire energy in the system remains same.
• When it strikes the ground, its energy is fully kinetic, till its velocity becomes zero.

Question 11.
Let us assume that you have lifted a suitcase and kept it on a table. On which of the following does the work done by you depend or not depend? Why?
a) The path taken by the suitcase
b) The time taken by you in doing so
c) The weight of the suitcase
d) Your weight
Answer:
We know that P.E. = mgh
a) The work done by you does not depend on the path taken by the suitcase, because the height from the ground to the top of the table is fixed in this case, (h constant)

b) The work done by you does not depend the time taken, in doing so, because the work done is same. If you take less time your power will be more otherwise the power is less.

c) The work done by you depends on the weight of the suitcase. As the weight of the suitcase increases, the work done will also increase (See the formula P.E. = mgh).

d) The work done by you depends on your weight, we know that a person with more weight can Mft the suitcase easily.

Question 12.
When you push your bicycle up an incline, the potential energy of the bicycle and yourself increase. Where does this energy come from? (AS 7)
Answer:
The energy inside our body causes increase in the P.E. of the bicycle and ourself.

As we are pushing the bicycle upon incline, the work done by the gravitational force is negative. Hence the energy loses.

Question 13.
Why does a person standing for a long time get tired when he does not appear to be doing any work? (AS 7)
Answer:
1) A person standing for a long time, does not appear to be doing any work, because there is no displacement.
2) Eventhough work has not been done, the person gets tired.
3) This is due to the utilization of energy produced in his body.

Question 14.
What is kinetic energy? Derive an expression for the kinetic energy of a body of mass ‘m’ moving at a speed ‘v’. (AS 1)
Answer:
Kinetic energy :
The energy possessed by an object due to its motion is called kinetic energy.

Numerical expression for K.E.:
1) Let us assume that an object of mass (m) is at rest on a smooth horizontal plane as shown in figure.

2) Let be displaced through a distence ‘s’ from the point A to B by a force (F) acting upon it in the direction of the displacement.
3) In the horizontal direction the net force ‘F_net‘ is equal to the force applied ‘F’.
∴ W = F_net.s = F.s …………. (1)
4) Let the work done on the object cause a change in its velocity from ‘u’ to ‘v’ anr the ‘acceleration produced be ‘a’.

8) As we Have assumed that object is at rest, then the initial velocity u = 0.
∴ W = \(\frac{1}{2}\) mv²

9) We know that K.E. of a body moving with certain velocity is equal to work done on the object to acquire that velocity from rest.

10) Thus the K.E. of an object of mass’m’ and moving with velocity V is equal to
K.E = \(\frac{1}{2}\) mv²

Question 15.
A free-fall object eventually stops on reaching the ground. What happens to its kinetic energy? (AS 1)
Answer:

• Its kinetic energy becomes ‘zero’.
• As the ball stops on reaching the ground, its final velocity ‘v’ becomes zero.
• Hence the K.E. = \(\frac{1}{2}\) mv² = \(\frac{1}{2}\).m.0 = 0

Question 16.
A man carrying a bag of total mass 25 kg climbs up to a height of 10 m in 50 seconds. Calculate the power delivered by him on the bag. (AS 1)
Answer:
Mass of the bag = 25 kg ; Height ‘h’ = 10 m
Acceleration due to gravity g = 9.8 m/s²
The P.E. of the man = mgh = 25 × 9.8 × 10 = 2450 J
The work done by the man is equal to the P.E. possessed by the man.
∴ The work done by the man (W) = 2450 J ; Time (t) = 50 sec.
∴ Power delivered by the man on the bag = \(\frac{\mathrm{W}}{\mathrm{t}}=\frac{2450 \mathrm{~J}}{50 \mathrm{sec}}\) = 49 watts

Question 17.
A 10 kg ball is dropped from a height of 10 m. Find (a) the initial potential energy of the ball, (b) the kinetic energy just before it reaches the ground and (c) the speed just before it reaches the ground.
Answer:
Mass of the ball = 10 kg ; It is dropped from a height h = 10 m
Acceleration due to gravity g = 9.8 m/sec²
a) The initial P.E. of the ball = mgh = 10 × 9.8 × 10 = 980 J
b) We know that the energy is conserved in a freely falling object at anywhere in its journey.
∴ The K.E. just before it reaches the ground = 980 J

c) K.E. just before it reaches the ground = 980 J ;
Speed = v m/s

Question 18.
Calculate the work done by a person in lifting a load of 20 kg from the ground and placing it 1 m high on a table. (AS 1)
Answer:
Mass of a load = 20 kg ; Height h = 1 m
Acceleration due to gravity = 9.8 m/s²
The work done by a person in lifting the load is equal to the P.E.
P.E. = mgh = 20 × 9.8 × 1 = 196 J

Question 19.
Find the mass of a body which has 5 J of kinetic energy while moving at a speed of 2 m/s. (AS 1)
Answer:
KE = 5 J
Speed v = 2 m/sec
Mass of the body = m kg.

Question 20.
A cycle together with its rider weighs 100 kg. How much work is needed to set it moving at 3 m/s?
Answer:
Mass of the bicycle with its rider = 100 kg ; Speed = 3 m/s Amount of work needed to set it moving is equal to its K.E.
K.E. = \(\frac{1}{2}\)mv² = \(\frac{1}{2}\) × 100 × 3 × 3 = 450 J
∴ 450 J work is needed.

Question 21.
When the speed of a ball is doubled its kinetic energy (AS 1)
A) remains same
B) gets doubled
C) becomes half
D) becomes 4 times
Answer:
D) becomes 4 time

Question 22.
Two bodies of unequal masses are dropped from the top of a building. Which of the following is equal for both bodies at any instant?
A) Speed
B) Force of gravity
C) Potential energy
D) Kinetic energy
Answer:
B) Force of gravity

Question 23.
A man with a box on his head is climbing up a ladder. The work done by the man on the box is ……….
A) Positive
B) Negative
C) Zero
D) Undefined
Answer:
A) Positive

Question 24.
A porter with a suitcase on his head is climbing up steps with uniform speed. The work done by the “weight of the suitcase” on the suitcase is ……
A) Positive
B) Negative
C) Zero
D) Undefined
Answer:
B) Negative

Question 25.
How will the increasing energy needs and conservation of energy influence international peace, cooperation and security? Discuss.
Answer:
1) The increasing energy needs and conservation of energy influence international peace, co-operation and security.

2) For example, many great nations depend on the gulf countries and many countries for fuel (Petrol, diesel, etc.). The need of fuel brings co-operation among the countries. Also the need of energy (electricity, fuel, etc.) link all nations to a small circle so that there comes the peace, co-operation and security.

3) Atomic energy, thermal energy, chemical energy, etc. bring unity among all nations.

Question 26.
How would you assess the role of energy conversion occurring naturally in maintaining ecological balance of nature?
Answer:

• The chemical changes in the sun is providing us the heat energy and light energy to the earth.
• The heat energy of the sun evaporates the water into water vapour. This helps us to get heavy rainfall.
• The solar energy is taken by the plant to change CO₂, water and chloroplast into starch which is the food of the plant. This process is called photosvnthesis.
• In the photosynthesis process the plant releases O₂ (oxygen).
• The leguminous (Pea plants) plants help the bacteria present at their roots. In return they help the plants to fix nitrogen in them The nitrogen cycle is maintained.
• From the above examples we can understand that the energy conversion is helpful in maintaining ecological balance of nature.

Question 27.
Collect pictures showing various situation where potential energy possessed by an object depends on its shape and position. Prepare a scrap book.
Answer:
Note : Students can collect pictures of different objects at different heights, with different shapes.
e.g.: 1) A stone on a hill.
2) A book on a table and a pen on a table, etc.
Paste these pictures in your scrap book.

Question 28.
Draw a diagram to show conservation of mechanical energy in case of free falling body.
Answer:

9th Class Physical Science 10th Lesson Work and Energy InText Questions and Answers

9th Class Physical Science Textbook Page No. 161

Question 1.
How are these works being done?
Answer:
All the works mentioned above are being done by utilizing human muscular energy or electrical energy.

Question 2.
What do you need to do these works?
Answer:
Both human beings or machines need energy to do work.

Question 3.
Where does the energy spent go ultimately?
Answer:
The energy spent will be converted into another form to complete the task.

Question 4.
Is there any transfer of energy while work is being done?
Answer:
Yes. We can observe the transfer of energy while work is being done. For example, in fan, electrical energy is converted into mechanical energy. In heater, electrical energy is converted into heat energy, etc.

Question 5.
Can we do any work without transfer of energy?
Answer:
No, we cannot do any work without transfer of energy.

9th Class Physical Science Textbook Page No. 162

Question 6.
What is work?
Answer:
When a force is applied on an object and a displacement is observed, the work is said to be done.

Question 7.
Why is there difference between general view of work and scientific view of work?
Answer:
In general view, work is said to be done while reading, writing, eating or even standing for some time. We cannot observe any displacement in these cases. But in scientific view, work is said to be done when there is a displacement in the direction of force applied.

9th Class Physical Science Textbook Page No. 163

Question 8.
Observe the following examples.
 
a) Are all the people mentioned in the above examples doing work ?
Answer:
No.
In example (1) and (2) there is displacement. Hence they are doing work.
In example (3) and (4) there is no displacement. Hence they are not doing any work.

b) How do you define work?
Answer:
Work is defined as the product of force and displacement.
W = F × s

9th Class Physical Science Textbook Page No. 165

Question 9.
What would be the work done when the force on the object is zero?
Answer:
We know work done W = F × s
Here F = 0
⇒ W = 0 × s = 0
∴ The work done is zero.

Question 10.
What would be the work done when the displacement of the object is zero?
Answer:
Work done W = F × s
Here s = 0
⇒ W = F × 0 = 0
∴ The work done is zero.

Question 11.
Can you give some examples, where the displacement of the object is zero?
Answer:

• When a boy pushes a wall, the displacement in the wall is zero.
• When a boy stands for some time at one place, then there is no displacement in the boy.
• Wind causes the swing in trees, but the tree does not have any displacement.

9th Class Physical Science Textbook Page No. 166

Question 12.
What happens to the speed of the ball while it moves up?
Answer:
The speed of the ball while it moves up decreases gradually, due to negative gravitational force acting on it.

Question 13.
What is the speed at its maximum height?
Answer:
The speed of the ball at its maximum height is zero.

Question 14.
What happens to the speed of the ball during its downward motion?
Answer:
During its downward motion, the ball starts from zero velocity*and its velocity gradually increases due to the positive gravitational force acting on it.

9th Class Physical Science Textbook Page No. 167

Question 15.
What is energy?
Answer:
Energy is the capability to do work.

Question 16.
How can we decide that an object possess energy or not?
Answer:
The capacity of doing work by an object on another object depends on position and state of the object which is doing work.

Question 17.
What will happen to the plate? Why?
Answer:
The plate breaks into pieces, because of the potential energy of the metal ball.

Question 18.
What changes do you notice? Why?
Answer:
The toy car is at rest before winding the key but the same toy gets energy to move when the key attached to it is wound up.

9th Class Physical Science Textbook Page No. 168

Question 19.
What could be the reason?
Answer:

• The reason for breaking up of the plate is the potential energy of the metal ball.
• The reason for moving the toy car is the potential energy of the spring in the toy.

Question 20.
Where does this energy go?
Answer:
The energy is transferred from one object to another.

Question 21.
Is there any energy transfer between the object doing the work and the object on which work has been done?
Answer:
Yes. In case of the toy car, the potential energy of the wounded spring is transferred to car and made the toy car to move.

Question 22.
Can any force do work without energy transfer?
Answer:
No.

9th Class Physical Science Textbook Page No. 169

Question 23.
Where do we get energy from?
Answer:
The Sun is the biggest natural and primary source of energy for us. Many other secondary sources are derived from the sun. We can also get energy from the interior of the earth and from tides of the sea.

Question 24.
Can you think of other sources of energy?
Answer:
The other natural sources of energy are wind energy, tidal energy, gravitational energy, etc. The artificial sources of energy are electrical energy, heat energy, muscular energy, etc.

Question 25.
Are there sources of energy which are not dependent on the Sun?
Answer:
Energy can exists in several forms like mechanical energy, light energy, thermal energy, sound energy, electrical energy, magnetic energy, etc. These energies, though they are artificial, they ultimately depend on the Sun.

Question 26.
Do you know why a person gets tired standing at a place for long time?
Answer:
Though the person standing is not doing any work externally, a lot of work is being done inside the body.

The muscles of the body become stretched when he stands for long time and heart has to pump more blood to muscles. This leads to loss of energy inside the body and hence he gets tired.

9th Class Physical Science Textbook Page No. 176

Question 27.
How do green plants produce food?
Answer:
Green plants produce food from sunlight, by means of photosynthesis.

Question 28.
How are fuels like coal and petroleum formed?
Answer:
Dead plants hurried deep below the earth’s surface for millions of years get converted to fuels like petroleum and coal which have chemical energy stored in them.

Question 29.
What kind of energy conversions sustain the water cycle in nature?
Answer:
Water cycle and conversation of energies :
1) The Sun heats water in oceans and seas. Then water evaporates as water vapour into the air.
Here potential energy converts into kinetic energy.

2) Rising air currents take the vapour up into the atmosphere. There cooler temperatures cause it to condense into clouds.
Here kinetic energy converts into potential energy.

3) Air currents move water vapour around the globe, cloud particles collide, grow and fall out as rain.
Here potential energy converts into kinetic energy.

4) Run off and ground water are stored as fresh water in lakes. Some precipitation falls as snow or hail.
Here kinetic energy converts into potential energy.

9th Class Physical Science Textbook Page No. 178

Question 30.
Do all of us do the work at the same rate?
Answer:
The rate of work done by all of us will not same, because the capacity to do work differs from person to person depending on the weight, nature of work, etc.

Question 31.
Is the energy spent by the force doing work the same every time?
Answer:
No. The energy spent by the force doing work depends on the capacity of the machine or the capacity of a person.

Question 32.
Do the machines consume or transfer energy at same rate every time while doing a particular work?
Answer:
No. For example, consider two grinders of different wattages. The grinder with high wattage can perform fast. In this the energy transfer is faster. The grinder with less wattage can perform slowly. In this the energy transfer is slow.

9th Class Physical Science Textbook Page No. 179

Question 33.
Whose argument is correct?
Answr:
Raheem’s argument is correct, in view of work done.
Second labourer’s argument is correct in view of working hours.

Question 34.
Is work done in two cases same?
Answer:
The work done in two cases is same.

Question 35.
Why is there a change in rate of doing work?
Answer:
The rate of doing work is different, as the two labourers completed in different times.

9th Class Physical Science Textbook Page No. 165

Question 37.
A wooden chair is dragged on the level floor and brought to the same place. Let the distance covered be ‘s’ and frictional force acted on the chair by the floor be T. What is the work done by the frictional force?
Answer:
The displacement of the chair is zero. Hence the work done is zero.

9th Class Physical Science Textbook Page No. 166

Question 38.
Lift an object up from the ground. Work done by the force exerted by you on the object moves it in upward direction. Thus the force applied is in the direction of displacement. However there exists a force of gravitation on the object at the same time
• Which one of these forces is doing positive work?
• Which one is doing negative work?
• Give reasons.
Answer:

• Force applied by us on the object, because the object moves in the direction of force applied.
• Force of gravitation on the object is doing negative work. Here the object is moving against to gravitational force.

9th Class Physical Science Textbook Page No. 169

Question 39.
What would happen if nature does not allow the transfer of energy? Discuss with few examples.
Answer:
If nature could not allow the transfer of energy, the normal life is not possible, e.g.:
1) If the solar energy is not transferred into chemical energy, in which plants prepare their food, we cannot find any plant on the earth. Life without plants is impossible. We can not get food, cloth, shelter and fresh air for our survival.

2) Water cycle is also an example of transfer of energy in nature. If this does not take place, ground water cannot be recharged, we cannot find any water further.

9th Class Physical Science Textbook Page No. 172

Question 40.
a) Why is it easier to stop a lightly loaded truck than heavier one that has equal speed?
Answer:
Due to its light weight, the truck with lighter load is easy to stop.

b) Does the kinetic energy of a car change more when it goes from 10 m/s to 20 m/s or when it goes from 20 m/s to 30 m/s?
Answer:
Case – I :
K.E._(I) = \(\frac{1}{2}\) × m × 10 × 10 = 50m J
K.E._(F) = \(\frac{1}{2}\) × m × 20 × 20 = 200m J
Difference in K.E. = 200m – 50m = 150m J

Case – II :
K.E._(I) = \(\frac{1}{2}\) × m × 20 × 20 = 200m J
K.E._(F) = \(\frac{1}{2}\) × m × 30 × 30 = 450m J
Difference in K.E. = 450m – 200m = 250m J

c) A person starts from rest and begins to run. The runner puts a certain momentum into himself. What is the momentum of ground? And the runner puts a certain amount of kinetic energy into himself. What is the kinetic energy of the ground?
Answer:
Here two cases arise.
Case – I :
In view of the observer, ground has no velocity. Hence the momentum and kinetic energy of the ground will be zero.

Case – II :
In view of the runner, ground has a velocity equal to the velocity of the runner.

1. The momentum of ground is equal to the momentum of the runner in magnitude but opposite in direction.
2. The K.E. of ground is also equal to the K.E of the runner in magnitude but opposite in direction.

9th Class Physical Science Textbook Page No. 175

Question 41.
Does the international space station have gravitational potential energy?
Answer:
International space station is situated in space where the gravitational force is zero. Hence the gravitational potential energy is zero.

9th Class Physical Science Textbook Page No. 178

Question 42.
a) Someone wanting to sell you a super ball claims’ that it will bounce to a height greater than the height from which it is dropped. Would you buy this ball? If yes explain, if not explain.
Answer:
Yes. I will buy this ball. When the applied force is more, the ball bounce to a height greater than the hefght from which it is dropped.

b) A ball, initially at the top of the inclined hill, is allowed to roll down: At the bottom its speed is 4 m/s. Next, the ball is again rolled down the hill, but this time it does not start from rest. It has an initial speed of 3 m/s. How fast is it going when it gets to the bottom?
Answer:
A ball start from the top of an inclined plane u} = 0 m/s; v, = 4 m/s.
Let the acceleration a’ and distance ’s’.
v₁² – u₁² = 2as …………. (1)
Now the ball is rolled down from the top of an inclined plane with a velocity 3 m/s.
∴ u₂ = 3 m/s; v₂ =?
Here the acceleration of the inclined plane is ‘a’ and the distance is ‘s’.

9th Class Physical Science Textbook Page No. 179

Question 43.
The work done by a force F₁ is larger than the work done by another force F₂. Is it necessary that power delivered by F₁ is also larger than that of F₂? Why?
Answer:
Power delivered by F₁ is may or may not be larger than F₂.
Two cases arise.
Case – I :
If the displacement is same, as F₁ > F₂, the power delivered by F₁ is larger than F₂.

Case – II :
If the displacement is different, power delivered by F₁ may not be larger than F₂.

9th Class Physical Science 10th Lesson Work and Energy Activities

Activity – 1

Question 1.
Read Ex : 1, 2, 3, and 4 from page 162 and 163. Now fill the following table.
Answer:

Activity – 2

Question 2.
Explain the relation between work done on an object and energy of the object with an activity.
Answer:

1. Take a hard spring and keep it on the table as shown in the figure.
2. Now compress the spring with your palm and release it after few seconds.
3. We will notice that when a spring is being compressed there is a change in its size.
4. When it is released it gains some energy and may even jump from the table.
5. The work done by your palm on the spring increases its energy and makes it to jump.
6. Thus we can conclude that the object which does work loses energy and the object on which work has been done gains energy.

Activity – 3

Question 3.
List the energy sources.
Answer:
The main source of energy is the sun. Many other secondary sources of energy are electrical energy, magnetic energy, chemical energy, muscular energy, geothermal energy, energy from fossil fuels, etc.

Activity – 4

Question 4.
Explain the energy of moving objects with an activity.
Answer:

1. Consider a metal ball and a hollow plastic block which are kept on a table side by side.
2. Now, suppose that the ball is separated from the block and brought to one end of the table and pushed to roll on the table with speed ‘v’.
3. We may notice that, the ball hits the plastic block and displaces it from point A to B.
4. Thus a moving ball is more energetic than the ball at rest.
5. We can conclude that a body possesses more energy when it is moving than when it is at rest.

Activity – 5

Question 5.
Explain potential energy with the help of a bow.
Answer:

1. Take a bamboo stick and make a bow as shown in figure.
2. Place an arrow made of a light stick on it with one end supported by the string of the bow and stretch the string gently and release the arrow.
3. We notice that the arrow gets separated from the bow and falls down on the ground.
4. Now place the arrow on the bow with one end supported by the string, applying more force and release the arrow.
5. We observe that the arrow flies with great speed into the air.
6. From this we can conclude that the bow in normal shape is not able to push the arrow, but when we stretch the string, it acquires energy to throw the arrow into air with great speed.
7. The energy acquired by the bow due to change in its shape is known as its potential energy.

Activity – 6

Question 6.
Write an activity to show the energy in stretched rubber band.
Answer:
Take a rubber band hold it at one end and pull it from the other end. Then release the rubber band at one of the ends.

When we release the rubber band, it strikes our hand with great force. This force is due to the energy acquired by the rubber band by stretching it.

Activity – 7

Question 7.
Show that the object at some height possesses energy.
Answer:

1. Take a heavy ball.
2. Drop it on a thick bed of wet sand from different heights from 25 cm to 1.5 m.
3. Observe the depression created by the ball on die bed of sand. Compare the depths of these depressions.
4. When the ball is dropped from different heights, the depressions created by the ball on the bed of sand will be different. ‘
5. As the height from which the ball was dropped increases, the depth of depression also increases.
6. Thus we can conclude that a body at some height possesses energy.

Activity – 8

Question 8.
List out the energy conversions in nature and in day to day life.
Answer:
Discuss various ways of energy conversions in nature as well as in our day to day activities and make a separate list of situations for natural conversions of energy and energy conversions in day to day life and write them in the given tables.
Table

Sl.No.	Situation of energy conversion in nature
1	Heat energy from the sun used for preparing food by plants gets con­verted into chemical energy.
2	Heat energy of the earth’s crust is useful in the formation of fossil fuels like petroleum, coal, etc.
3	Heat energy from the sun is converted into wind energy and wave energy.
4	Food we take will convert into energy.
5	Water cycle Heat energy → Water vapour → water (rain)

Table

Situation of energy conversion	Gadgets / appliances used for energy conversion
1. Conversion of electrical energy into mechanical energy	Electric fan
2. Conversion of mechanical energy into electrical energy	Dynamo
3. Conversion of chemical energy into electrical energy	Cell
4. Conversion of chemical energy into mechanical energy	Motor vehicles
5. Electrical energy into heat energy	Electric stove
6. Electrical energy into light energy	Bulb
7. Solar energy into electrical energy	Solar lamp
8. Wind energy to electrical energy	Wind mills
9. Gravitational potential energy to electrical energy	Hydro electric power

Activity – 9

Question 9.
Write an activity which shows the conservation of mechanical energy.
Answer:

1. Take a long thread say 50-60 cm long.
2. Attach a small heavy object like a metal ball at one end.
3. Tie other end to a nail fixed to the wall as shown in figure.
4. Now pull the bob of the pendulum to one side to the position A₁ and release it.
5. The bob swings towards opposite side and reaches the point A₂. It repeats the motion over and over again.
6. The potential energy of the bob is minimum at A and reaches maximum at A₁ because the height of the bob is maximum at that position.
7. When the bob is released from this point (A₁), its P.E. decreases and K.E. starts increasing slowly.
8. When the bob reaches the position A, its K.E. reaches maximum, and P.E. becomes minimum.
9. As the bob proceeds from A to A₂, its P.E. increases slowly and becomes maximum at A₂.
10. The total P.E. and K.E. at any point on the path of motion during the oscillation of the pendulum.
11. Thus the total mechanical energy in the system of pendulum remains constant.

Activity – 10

Question 10.
Calculate the total energy of free-fall at different heights.
An object of mass 20 kg is dropped from a height of 4 m. Compute the potential and kinetic energy in each case and write the values in the table. (Take g = 10 ms-2)

a) What do you say about total energy of system of freely falling body?
Answer:
In a freely falling body, the total energy of system (i.e. the sum of potential energy and kinetic energy) is same at any instance of its travel.

b) Is the mechanical energy conserved in the system?
Answer:
The sum of potential energy and kinetic energy at any instance of its travel is same. Hence we can say that the mechanical energy is conserved in the system.