Question

A block moving in air, explodes into two parts. Then just after explosion (neglect change in momentum due to gravity)

Statement $1$ :- The total momentum of the two parts must be equal to the momentum of the block before explosion.

Statement $2$ :- If no external force acts on a system, then the linear momentum of the system will be conserved.

• A. Statement $1$ is true, Statement $2$ is true, Statement $2$ is the correct explanation for Statement $1$.
• B. Statement $1$ is true, statement $2$ is true, statement $2$ is not the correct explanation for statement $1$.
• C. Statement $1$ is true, but statement $2$ is false.
• D. Statement $2$ is true, but statement $1$ is false.

Answer 1

The correct option is A Statement $1$ is true, Statement $2$ is true, Statement $2$ is the correct explanation for Statement $1$.

As we already know, if no external force acts on the system, then the linear momentum of the system will be conserved.
i.e If $F_{ext}=0$,
$\Delta P=0$
$\Rightarrow {\overrightarrow{P}}_{inital}={\overrightarrow{P}}_{final}$

Here, during the explosion, no external force is present. So, linear momentum will be conserved.

Initial momentum (before explosion) = Final momentum (after explosion)

Hence, both the statements are correct and statement $2$ is the correct explanation for statement $1$.