Assume that a person pouncing a ball represents a closed system. Which
statement best describes how the amounts of the ball's potential and kinetic
energy change?
A. Both the kinetic and potential energy of the ball increase.
B. The ball's kinetic energy increases as it falls and its potential
energy decreases.
C. Both the kinetic and potential energy of the ball decrease.
D. The ball's potential energy decreases as it rises and its kinetic
energy increases.