Kinetic energy: The coefficient of the restitution of an object is defined as the ratio of its outgoing to incoming speed when the object collides with a rigid surface. For an object with a coefficient of 0.78, what fraction of the object's kinetic energy is lost during a single collision?

Question

Quizplus · Accepted Answer

The coefficient of restitution (e) is 0.78, meaning the outgoing speed is 78% of the incoming speed. The kinetic energy is proportional to the square of the speed, so the fraction of kinetic energy retained is (0.78)^2 = 0.6084, meaning 60.84% is retained and 39.16% is lost. Thus, approximately 39% of the kinetic energy is lost.

Kinetic Energy: the Coefficient of the Restitution of an Object