The football hits the ground at 6.53 seconds
The height function of the football is given as:
[tex]f(t) = -4.9t^2 + 30t + 13[/tex]
When the football hits the ground, f(t) = 0 i.e. the height of the football is 0.
So, we have:
[tex]-4.9t^2 + 30t + 13 = 0[/tex]
Using a calculator, we have:
[tex]t = \{-0.41, 6.53\}[/tex]
The value of time (i.e. t) cannot be negative.
So, we have:
[tex]t = 6.53[/tex]
Hence, the football hits the ground at 6.53 seconds
Read more about quadratic functions at:
https://brainly.com/question/11441586
