A projectile is launched upward from a height of 960 feet with an initial velocity of 64 ft/s. The equation gives the height h after t seconds. Find the number of seconds until it returns to the ground.

Answer 1

-16t^2 + 64t + 960 = 0

-16(t^2 - 4t -60) =0
-16(t - 10)(t+6) =0
t = 10
t = -6
10 second