Afive-foot-tall boy tosses a tennis ball straight up from the level of the top of his he...

Afive-foot-tall boy tosses a tennis ball straight up from the level of the top of his head. Neglecting frictional forces, the subsequent motion is governed by the differential equation

If the object hits the ground 8 seconds after the boy releases it, find

(a) the time when the tennis ball reaches its maximum height.

(b) the maximum height of the tennis ball.