A Foul Ball Is Hit Straight Up into the Air

Essay

A foul ball is hit straight up into the air with a speed of 30 m/s, and air resistance is
negligible.
(a) Calculate the time required for the ball to rise to its maximum height.
(b) Calculate the maximum height reached by the ball above the point where it hit the bat.
(c) Determine the times at which the ball passes a point 25 m above the point where it was
hit by the bat.
(d) Explain why there are two answers to part (c).