Question

A toy rocket launched into the air has a height (h feet) at any given time (t seconds) as h=- 16t^2 + 160t until it hits the ground. At what time(s)is it at a height of 9 feet above the ground?

Answer 1

That means the rocket will take 8 seconds to return to the ground. That means the rocket will be at height = h(t) = 112 at t = 7 and t = 1. That means the rocket will be 112 feet above the ground after 1 second and after 7 seconds.