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 ___seconds for the ball to hit the ground.

Answer 1

4 seconds

Explanation:

When the ball hits the ground the height is 0

-16t² + 64t = 0

Divide both sides by -16

t² - 4t = 0

Factor out t

t(t - 4) = 0

From the zero product rule

t = 0 and t - 4 = 0

t = {0, 4}

The ball hits the gound after 4 seconds