Question

Why does an object balance at its center of mass?

Answer 1

Centre of mass

1. An object is balanced according to its mass distribution.
2. Center of mass is the region of the body where the whole mass of the body is assumed to be concentrated.
3. For symmetrical objects, the center of mass will always lie in the axis of symmetry.

The whole mass is assumed to be concentrated at that point because the object can be balanced by holding at that point.