Question

Derive an expression for kinetic energy of a body of mass 'm' moving at a speed 'v'.

Answer 1

Answer:

Very simple explanation

Let mass of the body be 'm'

Let initial velocity of the body be 'u'

Let final velocity of the body be 'v'

From the chapter motion, we know that-

2as=v sqaure-u square

Therefore, s=v square-u square÷2a

According to newton's 2nd law of motion,

F=ma

We know that, W=FS

W=ma×v square-u square÷2a

W=1/2×m(v square- u square)

If 'u'=0

W=1/2mv square

Therefore, kinetic energy=1/2mv square