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You are here: Home / Class 9 / Work and energy / Energy

Energy

Last Updated on March 20, 2019 By Mrs Shilpi Nagpal Leave a Comment

Question 1 Define the term energy?

Question 2 What is the S.I. unit of energy?

Question 3 Is energy a vector or scalar quantity?

Energy
Energy is the ability or capability to do work .
The sun is the biggest source of energy.

Ex:1)When an object is raised to a certain height it gets the capability to do work.

2)When a raised hammer fall on a nail placed on a piece of wood,it drives the nail into wood.

3)Children winding a toy and when the toy is placed on the floor,it starts moving.

In all these examples,energy is required to do work.
The amount of energy possessed by a body is equal to amount of work it can do when its energy is released.
The object which does the work loses energy and object on which work is done gains energy.

A body possesses energy can exert a force on another object.During this process,some of the energy of the body is transferred to the object.By gaining energy,the object moves and when object moves work is said to be done.

Energy is a scalar quantity.

The S.I. unit of energy is Joule(J).

1KJ = 1000 J

Filed Under: Class 9, Work and energy Tagged With: energy, joule

About Mrs Shilpi Nagpal

Author of this website, Mrs Shilpi Nagpal is MSc (Hons, Chemistry) and BSc (Hons, Chemistry) from Delhi University, B.Ed (I. P. University) and has many years of experience in teaching. She has started this educational website with the mindset of spreading Free Education to everyone.

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