Question 770139: A ball is dropped from a bridge 150 feet above a river. How long will it take for the ball to hit the surface of the water? Answer by Edwin McCravy(20054) (Show Source):
The formula is
h = ho - 16t²
h = the variable height the ball is above the river at variable time t.
ho = the height above the river that the ball is dropped = 150 ft.
When the ball hits the surface of the water is is 0 ft above the river.
So we set h = 0 and ho = 150 and solve for t
0 = 150 - 16t²
16t² = 150
t² =
Take the square root of both sides, (we don't need ± because
time is never negative.
t =
t =
t =
t = or 3.06 seconds approximately.
Edwin
