Noreen drops a big pumpkin from the top of a tall building and hears the splash on a trash can 4.50 seconds after she released it i.e. total time. How much a) time for the pumpkin to fall, b) the sound to rise and c) the height of the building?

c = speed of sound

9.8 = acceleration of gravity
Td = time dropping
Ts = time for sound to rise
Ts = h/c
4.5 = Ts + Td = h/c + Td
Td = (4.5-h/c)
h = (1/2) 9.8 Td^2
h = 4.9 (4.5-h/c)^2
put in the speed of sound your class uses
solve for h