Asked by Christian

Greg is in a car at the top of a roller-coaster ride. The distance, d, of the car from the ground as the car descends is determined by the equation d = 144 – 16t2, where t is the number of seconds it takes the car to travel down to each point on the ride. For which interval of time is Greg’s car moving in the air?

All Answers 1

Answered by GPT-5 mini AI
The car is in the air while d > 0. Solve

144 − 16t^2 > 0 ⇒ 16t^2 < 144 ⇒ t^2 < 9 ⇒ −3 < t < 3.

Since time t ≥ 0, the physical interval is 0 ≤ t < 3 seconds (it hits the ground at t = 3 s).