Question

A basketball of mass 0.0400 kg is dropped from a height of 5.00 meters to the ground and bounces back to a height of 3.00 meters .

A. On its way down, how much potential energy does the ball lose?

B. On its ways, how much potential energy does the ball regain?

Answer 1

A. The potential energy is defined as follows:

$$E_1 = mgh_1$$

where $m =0.0400kg$ is the mass of the ball, $g = 9.81m/s^2$ is the gravitational acceleration, $h_1 = 5.00m$ is the initial height. Thus, obtain:

$$E_1 = 0.04\cdot 9.81\cdot 5 \approx 1.96J$$

B. Similarly, on the way up:

$$E_2 = mgh_2 = 0.04\cdot 9.81\cdot 3 \approx 1.18J$$

Answer. A. 1.96J, B. 1.18J.