Question

A football is kicked straight up from a height of 5 feet with an initial speed of 55 feet per second. The formula h equals negative 16 t squared plus 55 t plus 5 describes the​ ball's height above the​ ground, h, in​ feet, t seconds after it was kicked. How long will it take for the football to hit the​ ground?

Answer 1

3.53 second

Step-by-step explanation:

The formula for the height is

`h=-16t^(2)+55t+5`

When it hits the ground, the height is zero.

So, put h = 0 in the above equation

`0=-16t^(2)+55t+5`

`16t^(2)-55t-5=0`

`t=\frac{+55\pm \sqrt{55^(2)+4* 5* 16}}{2* 16}`

`t=(+55\pm 57.84)/(2* 16)`

Take positive sign

t = 3.53 second.

Thus, the time taken to hit the ground is 3.53 second.