Calculus kinematics please help?

The height of a baseball hit straight up from the ground with an initial velocity of 64ft/s is given by h=f(t)=64t-16t^2, where t is measured in seconds after the hit.

a. Is this function one-to-one on the interval 0≤t≤4?

b. Find the inverse function that gives the time t at which the ball is at height h as the ball travels upward. Express your answer in the form t=f^-1(h)

c. Find the inverse function that gives the time t at which the ball is at height h as the ball travels downward. Express your answer in the form t=f^-1(h).

d. At what time is the ball is at a height of 30 ft on the way up?

e. At what time is the ball is at a height of 10 ft on the way down?

I really dont know how to do the question for b,c,d and e.