Question

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? It will take a0 seconds for the ball to hit the ground.

Answer 1

4

Explanation:

Answer 2

4 seconds

Explanation:

When the ball is on the ground h = 0, hence

- 16t² + 64t = 0 ( solve for t )

factor out - 16t

- 16t(t - 4) = 0

equate each factor to zero and solve for t

- 16t = 0 ⇒ t = 0

t - 4 = 0 ⇒ t = 4

the 0 solution is the height of the ball before being hit and

the time the ball takes to hit the ground is 4 seconds