Question

Does the center of mass change?

Answer 1

Yes, the center of mass change.

1. Centre of the mass of a body or system of a particle is defined as, a point at which whole of the mass of the body or all the masses of a system of particle appeared to be concentrated.”
2. If a system is not under the influence of any external force, the center of mass of the system will remain at rest or will move at constant velocity if it is already moving.
3. The system's center of mass only accelerates, if external forces are acting on the system.
4. If an external force acts on the body, then the center of mass accelerates obeying the rule $F=Ma$.
5. Hence, the center of mass has a moment acceleration $\overrightarrow{a}=\overrightarrow{\frac{F}{M}}$, in which $M$ is the mass of the rigid body and $\overrightarrow{F}$ is Force.
6. For example, when the human being is standing or bending, the position of the center of mass changes.
7. When an object is thrown into the air, although different parts of the object follow quite complicated paths, the center of mass will follow a parabola.

Hence the center of mass does change when an external force is acting on the body.