For this we almost have the following equation:
[tex]h = -16t ^ 2 + 25
[/tex]
We must match the equation to zero:
[tex]-16t ^ 2 + 25 = 0
[/tex]
From here, we clear the value of t.
We have then:
[tex]16t ^ 2 = 25
t ^ 2 = 25/16[/tex]
We discard the negative root because we are looking for time:
[tex]t = \sqrt{ \frac{25}{16} }
[/tex]
[tex]t = \frac{5}{4} [/tex]
Answer:
it will take him to reach the ground about:
[tex]t = \frac{5}{4} [/tex] seconds
