An elevator without a ceiling is ascending with a constant speed of 11 m/s. A boy on the elevator shoots a ball directly upward, from a height of 2.0 m above the elevator floor, just as the elevator floor is 23 m above the ground. The initial speed of the ball with respect to the elevator is 24.9 m/s.
(a) What maximum height above the ground does the ball reach?
(b) How long does the ball take to return to the elevator floor?