The height, h, in feet of a golf ball above the ground after being hit into the air is given by the equation, h = -16t 2 + 64t, where t is the number of seconds elapsed since the ball was hit. How many seconds does it take for the golf ball to hit the ground?

Answer 1

3 seconds?

Answer 2

it hits the ground when the height is zero, right?
-16t 2 + 64t = 0
-16t(t-4) = 0
so, what do you think?

Answer 3

So then t=4?