You have designed a rocket to be used to sample the local atmosphere for pollution. It is fired vertically with a constant upward acceleration of 15 m/s2. After 21 s, the engine shuts off and the rocket continues rising (in freefall) for a while. (Neglect any effects due to air resistance.) The rocket eventually stops rising and then falls back to the ground. You want to get a sample of air that is 11 km above the ground.

Question

You have designed a rocket to be used to sample the local atmosphere for pollution. It is fired vertically with a constant upward acceleration of 15 m/s2. After 21 s, the engine shuts off and the rocket continues rising (in freefall) for a while. (Neglect any effects due to air resistance.) The rocket eventually stops rising and then falls back to the ground. You want to get a sample of air that is 11 km above the ground.
(a) What is the highest point your rocket reaches?

Henry · Answer

a. h1 = 0.5a*t^2 = 7.5*21^2 = 3308 m V = a*t = 15 * 21 = 315 m/s. hmax = h1 + (V^2-Vo^2)/2g = 3308 + (0-315^2)/-19.6 = 8371 m.