Question

Jon is hitting baseballs. When he tosses the ball into the air, his hand is 5 feet above the ground. He hits the ball when it falls back to a height of 4 feet. The height of the ball is given by h = 5 + 25t - 16t^2, where h is measured in feet and t is measured in seconds. How many seconds after throwing the ball does Jon hit it?

Answer 1

`t=1.60\ sec`

Explanation:

Functions

We are given the function that relates the height of the ball and the time elapsed t. The function is:

`h = 5 + 25t - 16t^2`

We need to know the time needed for the height to reach 4 feet, that is h=4

`5 + 25t - 16t^2=4`

Rearranging

`16t^2-25t -1=0`

Solving for t

`\boxed{t=1.60\ sec}`

The other solution is negative and is discarded because t cannot be negative.