A toy 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 90m and acquired a velocity of 67 m/s. The rocket continues to rise in unpowered flight, reaches maximum height, and falls back to the ground. The upward acceleration of the rocket during the burn phase is closest to: 0.04 m/s² 50 m/s² 25 m/s² O 0.8 m/s² O 0.4 m/s²

Just 10 I did 11

13&14.

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Problem 4: Speed deamplifier. In the figure above on the right, block 1 of mass m1 slides along an x-axis on a frictionless floor at speed 4 m/sec.Then it undergoes a one-dimensional elastic collision with stationary block 2 of mass m2 = 2m1. Next, block 2 undergoes a one-dimensional elastic collision with stationary block 3 of mass mz = 4m1. What then is the speed of block 3? Answer: 16 m/sec or 1.78 m/sec.