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Question
Two friends on roller-skates are standing 5 m apart facing each other. One of them throws a ball of 2 kg towards the other, who catches it, How will this activity affect the position of the two? Explain your answer.
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Solution
Initially, the momentum of both of them is zero. The one who throws the ball will move backwards to conserve the momentum imparted on the ball. Now, the other one who catches it will also move backwards as he will experience a net force after catching the ball. Hence, the separation between them will increase.
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