Question

Two identical particles move towards each other with velocity 2v and v respectively. The velocity of the centre of mass is

• A. $v$
• B. $\frac{v}{3}$
• C. $\frac{v}{2}$
• D. $Zero$

Answer 1

The correct option is C $\frac{v}{2}$

${\overrightarrow{V}}_{cm}=\frac{m_1{\overrightarrow{V}}_1+m_2{\overrightarrow{V}}_2}{m_1+m_2}=\frac{m\left(2v\right)+m(-v)}{m+m}=\frac{v}{2}$