Question

Assertion :When there is no external force on a system, its kinetic energy must remain constant Reason: When there is no external force on a system its linear momentum must remain constant.

• A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
• B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
• C. Assertion is correct but Reason is incorrect
• D. Both Assertion and Reason are incorrect

Answer 1

The correct option is A Both Assertion and Reason are correct and Reason is the correct explanation for Assertion

when there is no ext. force acting on a system$,$ then momentum of system remain constant$.$

$K.E.=\frac{P^2}{2M}$

If $P$ is constant then $K.E$ is also converse$.$

Hence,

option $\left(A\right)$ is correct answer.