Concerning Newton's Cradle:
a) Determine the velocity of ball 2 just after the collision in terms of vi.
Also I am having problems with the following question: A boy moves on a skateboard at a constant velocity of 3 m/s. The combined mass of the boy and the skateboard is 40 kg. He catches a bag of flour of mass 5 kg that is thrown to him horizontally at 6 m/s. Determine the velocity of the boy after catching the bag of flour.
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