Consider a two-particle system with the particles having masses m1 and m2. If the first particle is pushed towards the centre of mass by a distance 'd', by what distance should the second particle be moved so as to keep the centre of mass at the same position?
Again, as we aleady know ,
△XCM = m1△X1+m2△X2m1+m2
△XCM = 0
Assuming leftards as negative and rightwards as potive
d' = −m1dm2
The negative sign indicates that m2 should be shifted by
(m1m2) d leftwards in order to keep the COM stationary.