Physics - Rotation Question with Solution | TestHub

Linear momentum of system of particle is ' 0 '. $=$ either $\left({\mathrm{m}}_1{\overrightarrow{\mathrm{v}}}_1+{\mathrm{m}}_2{\overrightarrow{\mathrm{v}}}_2+\dots \dots +{\mathrm{m}}_{\mathrm{n}}{\overrightarrow{\mathrm{v}}}_{\mathrm{n}}=0\right)$ or $\left|{\vec{v}}_1\right|=\left|{\vec{v}}_2\right|=\left|{\vec{v}}_3\right|=\left|{\vec{v}}_n\right|=0$

If K.E. of system of particle is ' 0 ', then each particle must be at rest. $\left|{\vec{v}}_1\right|=\left|{\vec{v}}_2\right|=\left|{\vec{v}}_3\right|\dots \dots ..\left|{\vec{v}}_n\right|=0$

So, option (3) is correct If $(\text{ K.E. }{)}_{\text{system }}=0$ then $(\overrightarrow{\mathrm{P}}{)}_{\text{system }}$ must be ${}^{\prime }{0}^{\prime }$.