A ball at the end of a string is swinging as a simple pendulum. Assuming no loss in energy due to friction, we can say for the ball that
A) the potential energy is maximum at each end of the motion.
B) the mechanical energy changes and is maximum where the kinetic energy is minimum.
C) the mechanical energy changes and is maximum where the kinetic energy is maximum.
D) the kinetic energy does not change but the potential energy does.

Question

Quizplus · Accepted Answer

In a simple pendulum, the potential energy is maximum at the highest points of the swing (each end of the motion) because the height from the ground is maximum there, and potential energy is directly proportional to height. Mechanical energy (sum of kinetic and potential energy) remains constant if there's no energy loss due to friction.

A Ball at the End of a String Is Swinging