Center of Mass

The position of COM is mass weighted average of the positions of particles. Mathematically, it is given as $\bf{r}_{COM} = \frac{\sum_i m_i \bf{r}_i}{M}$.

We can describe the translational motion of a rigid body as if it is a point particle with the total mass located at the COM—center of mass.

The center of mass (COM) is an important physical concept—it is the point about which objects rotate.

The COM (center of mass) of a system of particles is a geometric point that assumes all the mass and external force(s) during motion.