a ball is thrown upward at 96 feet per second from the top of a 100 foot building.

Question

1.when will the ball obtain maximum height

2. when will the ball hit the ground?

Answer 1

s = 100 + 96t - 16t^2

ds/dt = 96 - 32t
ds/dt = 0 when t = 3

s = 0 when

100 + 96t - 16t^2 = 0
when t = 6.9