Janelle stands on a balcony, two stories above Michael. She throws one ball straight up and one ball straight down, but both with the same initial speed. Eventually each ball passes Michael. Which ball, if either, is moving faster when it passes Michael? Explain.

Both balls have the same speed.

Explanation:

Janelle throws the two balls from the same height, with the same speed. Both balls will have the same potential and kinetic energy. Energy must be conserved. When the balls pass Michael, again they must have the same potential and kinetic energy.