Tony (of mass 45 kg) coasts on his bicycle (of mass 20 kg) at a constant speed of 7 m/s, carrying a 7 kg pack. Tony throws his pack forward, in the direction of his motion, at 5 m/s relative to the speed of bicycle just before the throw. What is the initial momentum of the system (Tony, the bicycle, and the pack) ? Answer in units of kg · m/s.

Question

Maritza

Physics

1 February, 12:12

Tony (of mass 45 kg) coasts on his bicycle (of mass 20 kg) at a constant speed of 7 m/s, carrying a 7 kg pack. Tony throws his pack forward, in the direction of his motion, at 5 m/s relative to the speed of bicycle just before the throw. What is the initial momentum of the system (Tony, the bicycle, and the pack) ? Answer in units of kg · m/s.

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Answers (1)

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Yosef Weiss · Answer 1

504 kg m/s

Explanation:

The total mass of the system (Tony, the bicycle, and the pack) is

M = 45 + 20 + 7 = 72 kg

Since momentum is defined as the product of mass and its speed. The total momentum of the system initially (before throwing the pack) when Tony is coasting at a speed of 7 m/s is:

P = MV = 72 * 7 = 504 kg m/s