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Given below are two statements : one is labelled as Assertion A and the other is labelled as Reason R. Assertion A : Body 'P' having mass M moving with speed 'u' has head-on collision elastically with another body 'Q' having mass 'm' initially at rest. If M ≪ m, body 'Q' will have a maximum speed equal to '2u' after collision. Reason R : During elastic collision, the momentum and kinetic energy are both conserved. In the light of the above statements, choose the most appropriate answer from the options given below :

1. A is not correct but R is correct.
2. Both A and R are correct but R is NOT the correct explanation of A.
3. Both A and R are correct and R is the correct explanation of A.
4. A is correct but R is not correct.

Correct answer: Both A and R are correct but R is NOT the correct explanation of A.

Solution

Assertion A is correct because, in an elastic collision where one body is much more massive than the other, the lighter body can indeed achieve a maximum speed of '2u'. Reason R is also correct as it states the principles of conservation of momentum and kinetic energy during elastic collisions, but it does not directly explain the specific outcome of A.

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