How to find time required for object to reach ground level

The question is:
A silver dollar is dropped from the top of a building that is 1362 feet tall.

For answers on a, b, and c are all correct, but I can't figure out how to find part d. If you could explain that to me I would appreciate it. Thanks in advance.

a) Determine the position and velocity functions for the coin.
Position: s(t) = -16t^2 + 1362
Velocity: V(t) = -32t
b) Determine the average velocity on the interval [1,2].
average Velocity = -48 ft/s
c) Find the instantaneous velocities when t = 1 and t = 2.
V(1) = -32 ft/s
V(2) = -64 ft/s
d) Find the time required for the coin to reach ground level.
*********How do I work this part?*******************
e) Find the velocity of the coin at impact.
If I'm right I would just put in the time it takes the coin to reach ground level into the velocity function here... If not please explain this too.

Thanks for the help with problem.

d) s(t) = -16t^2 + 1362
At ground level, s=0, so solve 0 = -16t^2 + 1362.
Discard the negative solution.

e) "If I'm right I would just put in the time it takes the coin to reach ground level into the velocity function here..." You are right, anD yes. v = -32t ft/s.

(All assuming air Tesistance can be ignored.)