Question

What do you mean by kinetic energy drive an expression or kinetic energy of body write si unit

Answer 1

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 = \frac{v^{2} - u ^{2} }{2a}

We know that ,

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

F = ma

W = ma × \frac{v^{2} - u ^{2} }{2a}

["a" gets cancelled ]

W = m × \frac{v^{2} - u ^{2} }{2}

= \frac{1 }{2} m[v² - u² ]

When , initial velocity , u = 0

W = \frac{1 }{2} mv²

K.E = Work done

= \frac{1 }{2} mv²