Question

A ball is thrown from the top row of seats in a stadium. The function h(t)=-16t2+48t+160 gives the height, t, in feet, of the ball t seconds after it is thrown. How long will it be before the ball hits the ground?

Answer 1

t = 5 s

Explanation:

The function that gives the height in feet of the ball t seconds after it is thrown is :

`h(t)=-16t^2+48t+160`

We need to find how long will it be before the ball hits the ground. When it hits the ground, its height will be equal to 0.

So,

`-16t^2+48t+160=0`

We need to solve this equation. When we solve, we get its solution as shown in the figure. We can see that t = -2 s and t = 5 s.

t = -2 s is not possible.

Hence, the ball will hit the ground before 5 seconds.