Question

a ball is dropped vertically from a height h. when it rebounds from the floor it attains a maximum height of $\frac{2}{3}$ h. what statement is true?
both conservative and nonconservative forces act on the ball.
only nonconservative forces act on the ball.
only conservative forces act on the ball.

Explanation:

Conservative forces like gravity act on the ball during its motion up - down. Non - conservative forces such as air resistance and the energy lost during the impact with the floor also act on the ball. Since the ball does not return to its original height $h$, some energy is dissipated by non - conservative forces.

Answer:

Both conservative and nonconservative forces act on the ball.