Center of Mass, Momentum & Collision

JEE Main level, single correct, medium

102 of 130

Question 102 of 130

Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R.
Assertion A : Body PP having mass MM moving with speed uu has head-on collision elastically with another body QQ having mass mm initially at rest. If m≪Mm≪M, body QQ will have a maximum speed equal to 2u2u 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:

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Answer: (C) Both A and R are correct and R is the correct explanation of A

For e=1e=1 & second body at rest
V2=2m1u1m1+m2=2u(M)M+m≃2u{V}_{2}=\dfrac{2{m}_{1}{u}_{1}}{{m}_{1}+{m}_{2}}=\dfrac{2u\left(M\right)}{M+m}≃2u
Since M>>mM\gt \gt m

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