Question

When a body is falling freely under gravity, the total mechanical energy remains constant because of which of the following?

(a) Law of conservation of energy

(b) Unification of force

(c) Electromagnetic force

(d) Gravity

This question was posed to me in an internship interview.

This key question is from Dimensional Analysis in portion Advanced Engineering Materials of Engineering Physics II

Answer 1

The correct answer is (a) Law of conservation of energy

To explain: According to the law of conservation of energy, energy can neither be created nor can it be destroyed but it can be changed from one form to another. When a body falls freely, under gravity, its potential energy gradually changes into kinetic energy. But its total mechanical energy remains constant at any point of its motion.