An object hits a wall and bounces back with half of its original speed.What is the ratio of the final kinetic energy to the initial kinetic energy of the object?
A)1/2
B)1/4
C)1/8
D)1/16

Question

Quizplus · Accepted Answer

The final kinetic energy of the object is proportional to the square of its velocity, so if the object bounces back with half of its original speed, its final kinetic energy will be $(1/2)^2 = 1/4$ of its original kinetic energy. Therefore, the ratio of the final kinetic energy to the initial kinetic energy is 1/4, which corresponds to choice B.

An Object Hits a Wall and Bounces Back with Half