Question

A body is dropped from a certain height. When it loses U amount of its energy, it acquires a velocity ‘v’. The mass of the body is

Answer 1

the lost energy is converted into kinetic energy

U = mv² / 2

m = 2U / v²

Answer 2

The mass of the body is 2u/v²

As per the law of energy conservation -

Initial total energy = final total energy or

The loss in potential energy = gain in kinetic energy

U = 1/2mv²

Ui + 0 = Uf + 1/2mv²

Ui - Uf = 1/2mv²

U = 1/2mv²

therefore, mass of the body

= m = 2u/v²

Hence, the mass of the body is 2u/v².