Physics
posted by Allyssa .
A ball is thrown horizontally at 12.2 m/s from the roof of a building and lands 21.0 m from the base of the building. How high is the building?

Xo = 12.2 m/s.
Range = 21 m.
Range = Xo * Tf = 21 m.
12.2 Tf = 21
Tf = 1.72 = Fall time.
h = 0.5g*Tf^2 = 4.9 * 1.72^2 = 14.5 m. 
A ball is thrown horizontally fron the roof of a building 7.5 tall and lands 9.5m from the base. What was the balls initial speed?

you're stupid