For e=1 & second body at rest
V2=m1+m22m1u1=M+m2u(M)≃2u
Since M>>m
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…
JEE Main 2021 — Physics Mechanics
2021mcqeasy
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:
Official previous-year question
Held on 26 Feb 2021 · Verified 6 Jul 2026.
Options
- A
A is correct but R is not correct.
- B
A is not correct but R is correct.
- C
Both A and R are correct and R is the correct explanation of A
- D
Both A and R are correct but R is NOT the correct explanation of A
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