Answer
It takes 3 seconds for the diver to reach the ocean surface.
Work Step by Step
For $h = −16t^2 + 144$, $h$ is to be measured from the ocean surface up and when the diver reaches the ocean, $h=0$.
Therefore,
$0 = −16t^2 + 144$
$16^2 = 144$
$t^2 = 9$
$t = ±3$
$t = 3$ or $t = −3$ (rejected)
Thus, it takes 3 seconds for the diver to reach the ocean surface.
