Question

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?

Answer 1

Answer:

0<t<3

Step-by-step explanation:

D on Edge

Answer 2

D = 144 - 16t^2
144 - 16t^2 ≥ 0
16(9 - t^2) ≥ 0
9 - t^2 ≥ 0
9 ≥ t^2
t ≥ + or -3

Required interval is 0 ≤ t < 3