Physics · SYSTEMS OF PARTICLES AND ROTATIONAL MOTION

If the origin of the coordinate frame of reference is chosen at the centre of mass of a system of \( n \) particles, then the sum \( \sum_{i=1}^{n} m_i \mathbf{r}_i \) is equal to:

1. A
   \( M\mathbf{R} \)
2. B
   \( \frac{1}{M} \)
3. C
   \( 0 \)
4. D
   \( \sum_{i=1}^n m_i \)