Explain the physical significance of the equation `MvecA=vecF_(ext)`, where 'M' is the mass of the whole rotating body and `vecA` is the acceleration of the centre of mass of the system of particles.

Explanation

The equation signifies the fact that the centre of mass of a system of particles moves as if all the mass of the system was concentrated at the centre of mass and all the external forces were applied at that point.
In the above expression `vecF_("ext")=vecF_1+vecF_2+......+vecF_n` and internal forces exerted by the particles occur in equal and opposite pairs so that they cancel out each other.