Given below are two statements: one is labelled as Assertion A an… - Vidyadip

MCQ

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:

A
$A$ is not correct but $R$ is correct.
B
Both $A$ and $R$ are correct but $R$ is $NOT$ the correct explanation of $A$.
✓
Both $A$ and $R$ are correct and $R$ is the correct explanation of $A$.
D
$A$ is correct but $R$ is not correct.

✓

Answer

Correct option: C.

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

c
For $e =1$ and second body at rest

$V_{2}=\frac{2 m_{1} u_{1}}{m_{1}+m_{2}}=\frac{2 u(M)}{M+m} \simeq 2 u$

Since $M > >m$

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