Question

Gianna is going to throw a ball from the top floor of her middle school. When she throws the hall from 48 feet above the ground, the function h(t)=-16t^2+32t+48 models the height,h, of the ball above the ground as a function of time,t. Find the times the ball will be 48 feet above the ground.

Answer 1

So, the times the ball will be 48 feet above the ground are t = 0 and t = 2.

Explanation:

The height h of the ball is modeled by the following equation

`h(t)=-16t^2+32t+48`

The problem want you to find the times the ball will be 48 feet above the ground.

It is going to be when:

`h(t) = 48`

`h(t)=-16t^(2)+32t+48`

`48=-16t^(2)+32t+48`

`0=-16t^(2)+32t+48 - 48`

`16t^(2) - 32t = 0`

We can simplify by 16t. So

`16t(t-2)= 0`

It means that

16t = 0

t = 0

or

t - 2 = 0

t = 2

So, the times the ball will be 48 feet above the ground are t = 0 and t = 2.