from 4 feet above a swimming pool, susan throws a ball upward witha velocity of 32 feet per second. how long does it take the ball to reach the water?

Answer 1

(Vf)^2 = Vo^2 + 2gd = 0,
(32)^2 - 2*32d = 0,
1024 - 64d = 0,
-64d = -1024,
d(up) = 16ft.

Vf = Vo + gt = 0,
32 - 32t = 0,
-32t = -32,
t(up) = 1s.

d(down) = 4 + 16 = 20ft.

d = Vo + 0.5gt^2 = 20ft.
d = 0 + 0.5*32t^2 = 20,
16t^2 = 20,
t^2 = 1.25,
t(down) = 1.12s.

t(up) + t(down) = 1 + 1.12 = 2.12s =
time for ball to reach water.