Answer:
[tex]t_1 = 0.28 s[/tex]
[tex]t_2 = 7.72 s[/tex]
Explanation:
Given that height of the projectile as a function of time is
[tex]h = -16 t^2 + 128 t + 112[/tex]
here we know that
h = 147 ft
so from above equation
[tex]147 = -16 t^2 + 128 t + 112[/tex]
[tex]16 t^2 - 128 t + 35 = 0[/tex]
now by solving above quadratic equation we know that
[tex]t_1 = 0.28 s[/tex]
[tex]t_2 = 7.72 s[/tex]