Question

Derive an expression for the kinetic energy of a body moving with a uniform velocity.

Answer 1

Answer:

Explanation:

Consider a body of mass "m" moving with an initial velocity "u".

A constant force "F" acts on it and the velocity changes to "v".

Let "s" be the distance covered and "a" be the constant acceleration

We know that

v² - u² = 2as

s =  v² - u²/2a

We know that ,

Work done = Force(F) × displacement (s)

F = ma

W = ma ×  v² - u² /2a

["a" gets cancelled ]

W = m ×  v² - u² /2a

= 1/2 m[v² - u² ]

When , initial velocity , u = 0

W = 1/2 mv²

K.E = Work done

=  1/2 mv²