A rock is thrown down with an initial speed of 30.0ft/s from a bridge to the water below. It takes 3.50s for the rock to hit the water. (a) Find the speed (in ft. /s) of the rock as it hits the water. (b) How high is the bridge above the water?

Answer 1

a. V = Vo + g*t = 30 + 32*3.5 = 135 Ft/s

b. h = Vo*t + 0.5g*t^2
h = 30*3.5 + 16*3.5^2 = 301 Ft.