A moving particle is subject to conservative forces only. When its kinetic energy decreases by 10 J, what happens to its mechanical energy?
A) It increases by 10 J.
B) It decreases by 10 J.
C) It increases, but not necessarily by 10 J.
D) It decreases, but not necessarily by 10 J.
E) It remains the same.

Question

Quizplus · Accepted Answer

In a system where only conservative forces are acting, the mechanical energy (sum of kinetic and potential energy) remains constant. If the kinetic energy decreases, the potential energy increases by the same amount, leaving the total mechanical energy unchanged.

A Moving Particle Is Subject to Conservative Forces Only