math + physics problem

20. A ball with mass 0.15 kg is thrown upward with initial velocity 20 m/s from the roof of a building 30 m high. Neglect air resistance. 

22. Assume that the conditions are as in Problem 20 except that there is a force due to air resistance of magnitude (v^2)/1325 directed opposite to the velocity, where the velocity v is measured in m/s.

(a) Find the maximum height above the ground that the ball reaches.

(b) Find the time that the ball hits the ground. (you can use wolframalpha)

I only need help with 22.