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JEE Main202126 Feb 2021Morning ShiftPhysicsCenter of Mass, Momentum and CollisionActual

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 2 u after collision. Reason R : During elastic collision, the momentum and kinetic energy are both conserved. In the

Options

  1. AA is correct but R is not correct.
  2. BA is not correct but R is correct.
  3. CBoth A and R are correct and R is the correct explanation of A
  4. DBoth A and R are correct but R is NOT the correct explanation of A

Correct answer

C. Both A and R are correct and R is the correct explanation of A

Step-by-step solution

For e = 1 & second body at rest V 2 = 2 m 1 u 1   m 1 + m 2 = 2 u M M + m ≃ 2 u Since M > > m

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