Two hockey players are about to collide on the ice. One player has a mass of 70 kg and is traveling at 1.4 m/s north. The other has a mass of 75 kg and is
traveling at 1.0 m/s south. The system consists of the two hockey players.
According to the law of conservation of momentum, what is the total
momentum of the system after they collide? Assume the collision is an
elastic collision.

The total momentum before and after is the same.
It is equal to (70x1.4) - (75x1) = 98-75 = 23 Kg m/s north

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