Question

After t seconds, a ball tossed in the air from the ground level reaches a height of h feet given by the equation h = 144t-16t^2. After how many seconds will the ball hit the ground before rebounding?

Answer 1

Answer:

9 seconds.

Step-by-step explanation:

When the ball hits the ground before rebounding its height = 0, so:

144t - 16t^2 = 0

-16t(t - 9) = 0

t = 0 ,  9 seconds.

t = 0 corresponds to the times when it was first thrown. T = 9 seconds is the answer.

Answer 2

Answer:

h(t) = 144·t - 16·t^2 = 16·t·(9 - t) = 0

9 - t = 0 --> t = 9

The ball will hit the ground after 9 seconds.