Question

a football is fired upward with an initial speed of 800 feet per second. It is given that h=-12t^2+360t (h is the height of the football at any given time).what will you set h equal to in the equation to to find how many seconds it takes the football to hit the ground?

Answer 1

30 s

Explanation:

When the ball hits the ground h=0. To find the time t when this happens we must solve the equation h=0.

●h= 0

● -12t^2+360t =0

● t(-12t +360) = 0

● t = 0 or -12t +360 =0

● t=0 or -12t = -360

● t=0 or 12t =360

● t=0 or t=360/12

● t=0 or t= 30

The equation has two solutions.

The ball was fired with an initial speed of 800 feet per second so it cannot hit the ground at t=0.

So the ball hits the ground after 30 s.