A girls throws a tennis ball straight into the air with a velocity of 64 feet/sec. If acceleration due to gravity is −32 ft/sec2, how many seconds after it leaves the girl's hand will it take the ball to reach its highest point? Assume the position at time t = 0 is 0 feet.

Answer 1

h(t) = 64t-16t^2
so, at max height, dh/dt=0.

So, find t for that.

Answer 2

2 seconds :)

Answer 3

2 seconds