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Delhi Public School Sector-V, Bokaro Steel City Session-2020-21 ,Subject- General Science Class- V E-Content Date- 04/0

Delhi Public School Sector-V, Bokaro Steel City Session-2020-21 ,Subject- General Science Class- V E-Content Date- 04/0

Delhi Public School

Sector-V, Bokaro Steel City

Session-2020-21 ,Subject- General Science

Class- V E-Content Date- 04/01/2021 to 09/01/2021

Ls-14 Simple Machines

Force- A push or pull applied on an object is called force.

Effects of force-

1) Force makes an object move. For example, a girl hit a ball with the help of her leg and makes it roll.

2) Force stops a moving object. For example, a goalkeeper stops the ball to avoid the goal.

3) Force can change the direction of a moving object .For example , a football player changes the direction of a moving ball by hitting it with force in a different direction.

4) Force can change the shape of an object. For example, a child is playing with clay. He wants to make a house of clay. He will apply force on the clay to make the wall of that house, the stairs, the roof etc. Therefore, the shape of clay will be changed every time after applying force.

Types of forces- There are various types of forces- gravitational , electrostatic , frictional ,magnetic, muscular , elastic and buoyant forces are very common examples .

Gravitational force- Force with which an object pulls another object is called gravitational force. For example, if we throw anything upwards, it always come down because of the earth’s gravitational force.

Frictional force-Force which works in opposite side of motion of a body is called frictional force. For example, a moving car is stopped by applying brakes. The car slows down and eventually stops because of the friction between the brakes and the wheels. This force is called frictional force. Rough surface offers more friction. Smooth surface offers less friction.

Advantages of friction-

1) Friction help us in walking on the floor. When you walk on the floor, it holds your slippers to the ground and allows you to walk.

2) It helps in writing . You cannot move a pencil without friction with paper. An eraser uses friction to rub off the mistakes.

3) Without friction, you cannot start a car or stop it.

Disadvantages of friction-

1) Excess friction can make it difficult to slide a box across the floor, ride a bicycle or walk. 2) Any device that has moving parts can wear out rapidly due to friction such as the soles of our shoes, pencils and erasers.

Electrostatic force-

The opposing force between two charged particles at a distance is called electrostatic force. For example, when we rub a piece of paper with the oil in our head with the help of a comb produces electrostatic force. Electrostatic force

Magnetic force- The force with which the magnet attracts certain materials , such as iron, cobalt and nickel, is called magnetic force.

Magnetic force

Muscular force-Muscular force is applied when muscles are used to push, pull, twist , lift or stretch an object.

When you lift a bucket from the floor , the force exerted by the muscles of our body is known as

muscular force. Muscular force being used to lift books

Elastic force- Elasticity is the ability of a material to return to its original shape after being stretched or compressed . A stretched spring or a rubber band regains its original shape and size after being released because of elastic force.

Buoyant force- Buoyant force is an upward force that is produced by surrounding gas or liquid on

an object enabling the object to float or rise up.

The best example of buoyant force is boats and ships sailing in the sea.

Work-Work is said to be done only when force applied on an object causes it to move through a distance. For example, a horse pulling a cart, a man pushing a wheel chair and a weightlifter lifting a barbell.

Horse pulling a cart A man pushing a wheel chair A weightlifter lifting a barbell

Work = amount of force X distance moved

Assignment

I) Fill in the blanks :-

1) The opposing force between two charged particles at a distance is called ------force.

2) Force which works in opposite side of motion of a body is called ------force.

II) Name the type of force:-

1) Pushing a car . 2) An apple falling onto the ground.

3) Using a catapult. 4) Boats and ships sailing in the sea .

III) Answer the following questions :-

Q-1 Define:- a) Gravitational force b) Work Q-2 What is force and what are its effects?

Q-3 What are the advantages and disadvantages of friction?

------X------X------X------

DELHI PUBLIC SCHOOL B.S.CITY SUB - SOCIAL STUDIES(SESSION-2020-2021) CLASS- V E-content for the week- from 28/12/20 to30/12/20 TOPIC - WINS FREEDOM SUB-TOPIC - NON - COOPERATION MOVEMENT, ** Content of the above lesson NON-COOPERATION MOVEMENT # In 1920, Gandhiji started the Non-Cooperation Movement. He asked the people to disobey laws, boycott foreign goods and clothes, government schools and colleges.He asked them to weave and become self- sufficient. # In the year 1922, on 4th February some people set fire to a police station in Chauri Chaura (Uttar Pradesh). Around 22 policemen died. # Gandhiji called off the movement immediately as he was against any kind of violence. # Dr., , Sardar , , C.Rajgopalachari, Maulana Azad, Chittaranjan and supported Gandhiji. SIMON COMMISSION # Simon Commission was a group of people led by a British politician Sir John Simon. It was appointed to review the law and order of the country which was getting out of control and to bring out new reforms. # The Indians were against this commission because not even a single Indian was made a member of it. # In 1929, when the Simon Commission arrived in India , it was greeted with the slogan, " Simon Go Back." # was badly injured in police lathi-charge while protesting against this commission at Lahore and later died due to his injuries. # A new group of very young revolutionaries like , Raj Guru, Sukhdev, BK Dutt, and became active and popular during this time. ** Read the above content carefully and answer the following questions :-

I. Fill in the Blanks:- (Write the complete sentence in your S.St copy)

1. In 1920, Gandhiji started the ______Movement. 2. The Indians were against ______commission because not even a single Indian was made a member of it. II. Question and answer:- (Note down the question also)

1. What was the Non-Cooperation Movement all about? Name the leaders who supported Gandhiji.

Ans:- In 1920, Gandhiji started the Non-Cooperation Movement. He asked the people to disobey laws, boycott foreign goods and clothes, government schools and colleges.He asked them to weave khadi and become self- sufficient. Dr.Rajendra Prasad, Motilal Nehru, Sardar Vallabhbhai Patel, Sarojini Naidu, C.Rajgopalachari, Maulana Azad, Chittaranjan Das and Jawaharlal Nehru supported Gandhiji.

______xxxxxx______

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