Question

The position vectors of two identical particles with respect to the origin in three dimensional coordinate system are \( \vec{r}_1 \) and \( \vec{r}_2 \). The position vector of centre of mass of the system is given by

• A. $\vec{r}_1 + \vec{r}_2$
• B. $\frac{\vec{r}_1 - \vec{r}_2}{2}$
• C. $\vec{r}_1 - \vec{r}_2$
• D. $\frac{\vec{r}_1 + \vec{r}_2}{2}$
• E. $\frac{\vec{r}_1 + \vec{r}_2}{3}$

Hint:

For identical masses, COM is simply the average of their position vectors.

Answer 1

The Correct Option is D