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