Learn about new technologies! # A rigid body, under the action of external forces, can be replaced by two masses placed at a fixed distance apart. The two masses form an equivalent dynamical system, if

The sum of the two masses is equal to the total mass of body

The centre of gravity of the two masses coincides with that of the body

The sum of mass moment of inertia of the masses about their centre of gravity is equal to the mass moment of inertia of the body

All of the above