Rita throws a ball straight up into the air and catches it at the same position from which she threw it. The ball has 18 J of mechanical energy when it leaves her hand. If no energy is lost due to friction, which statements about the energy of the ball are true? Choose four correct answers.
Answer
A
The total mechanical energy of the ball stays constant.
B
The kinetic energy is less when the ball is thrown than when it is caught.
C
The mechanical energy decreases as the ball moves up and increases as the ball comes down.
D
The kinetic energy increases as the potential energy decreases.
E
The kinetic energy decreases as the potential energy increases.
F
The potential energy at the top of the ball’s motion is 18 J.