Question

Define kinetic energy and derive the equation.

Answer 1

Kinetic energy- energy which a body possess by virtue of being in motion is called kinetic energy.
Kinetic energy=1/2mv square

Answer 2

Kinetic energy is a body moving with a certain velocity is equal to the work done on it to make it aacquire that velocity.

Derivation

Vsquare-usquare=2as

This gives

S=v^2-u^2/2a

We know that f=ma

Using 1 and 2 equation we can write

W= ma v^2-u^2/2a

W= 1/2 m v^2-u^2

It is clear that the work done is equal to the change in kinetic energy of an object

U=0

W=1/2mv^2

Kinetic energy =1/2mv^2