Question

The total energy change of a body which covers a vertical height is constituted completely by the potential energy change only when ______

(a) It moves slowly

(b) It moves quickly

(c) It moves for some time, then rests, then moves again

(d) It moves with a decreasing velocity

The question was asked by my college director while I was bunking the class.

The above asked question is from Work-Energy Theorem topic in section Work, Energy and Power of Physics – Class 11

Answer 1

Correct answer is (a) It moves slowly

For explanation: The total change in energy is constituted by the changes in potential and kinetic energies. When the body is moving slowly, it implies that the body is moving with such a small velocity that the square of the velocity in the expression of kinetic energy becomes negligible. Hence, the total change in the energy is constituted by the total change in the potential energy.