Question

A tennis ball is dropped from a certain height. Its height in feet is given by h, of, t, equals, minus, 16, t, squared, plus, 1156h(t)=−16t
2
+1156 where tt represents the time in seconds after launch. How long is the ball in the air?

Answer 1

Set h(t)=0 and solve:

0 = −16t^2 + 1156
16t^2 = 1156
t^2 = 1156/16 = (34/4)^2 = (17/2)^2

t = 17/2 = 8.5 seconds (take the positive root).