Factoring, you have
h(t) = -16(t^2 -2 -8) = -16(t -4)(t +2)
The ball hits the ground when h(t) = 0, so
0 = -16(t -4)(t +2)
t = 4 or -2
The positive solution is the one of interest.
It will take 4 seconds for the ball to hit the ground.
h(t) = -16(t^2 -2 -8) = -16(t -4)(t +2)
The ball hits the ground when h(t) = 0, so
0 = -16(t -4)(t +2)
t = 4 or -2
The positive solution is the one of interest.
It will take 4 seconds for the ball to hit the ground.