[SOLVED] Polynomial time/height

Hey guys, I need help with this!

A ball is dropped from top of a building. Its height from the ground (in feet) after t

seconds is given by H (t) = – 16 t^2 + 320.

a) Graph this function.

b) What is an appropriate domain for this function?

c) How tall is the building?

d) How high is the ball after traveling 2 seconds?

e) When does the ball reach the ground?

f) What is the range of this function?

g) Another ball is thrown upward from top of the same building. Give an example of

a function G where G(t) gives the height of the ball form the ground after t

seconds.