Particle of masses 2 kg, 2 kg, 1 kg and 1 kg are placed at the corners A, B, C, D of a square of side L as shown in Fig. Find the centre of mass of the system.

Explanation

If A is taken as origin
Then xcm `=(m_(1)x_(1)+m_(2)x_(2)+m_(3)x_(3)+m_(4)x_(4))/(m_(1)+m_(2)+m_(3)+m_(4))`
`=(2.0+2.L+1.L+1.0)/(6)=(1)/(2)L`
`ycm=(m_(1)y_(1)+m_(2)y_(2)+m_(3)y_(3)+m_(4)y_(4))/(m_(1)+m_(2)+m_(3)+m_(4))`
`=(2.0+2.0+1.L+1.L)/(6)=(L)/(3)`