Physics - Center of Mass Question with Solution | TestHub

Statement-2 provides the correct formula for the velocity of the center of mass. If one particle is at rest ($v_1=0$) and the other is moving ($v_2\ne 0$), then $V_{CM}=\frac{m_1(0)+m_2{v}_2}{m_1+m_2}=\frac{m_2{v}_2}{m_1+m_2}$. Since $m_2\ne 0$ and $v_2\ne 0$, $V_{CM}$ cannot be zero. Thus, the center of mass must be moving. Statement-2 correctly explains Statement-1.