Atest rocket is launched vertically from ground level (y = 0 m), at time t = 0.0 s. the rocket engine provides constant upward acceleration during the burn phase. at the instant of engine burnout, the rocket has risen to 49 m and acquired a velocity of 30 m/s how long did the burn phase last? a: 2.6 s b: 2.3 s c: 3.3 s d: 3.6 s e: 2.9 s

The rocket starts at rest, so its initial velocity is 0. If the burn phase lasts seconds, then during this interval the rocket's velocity is

and its position is

So we have

and the answer is C.

the independent variable, the one that is intentionally manipulated, is whether or not the car hits the barrier.

the dependent variable, the one that you measure the response in, is the distance that the washers travel.