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

Aperson stands on a platform, initially at rest, that can rotate freely without friction. the moment of inertia of the person plus the platform is ip. the person holds a spinning bicycle wheel with its axis horizontal. the wheel has moment of inertia iw and angular velocity ωw. take the ωw direction counterclockwise when viewed from above. part a what will be the angular velocity ωp of the platform if the person moves the axis of the wheel so that it points vertically upward?