Question

Find the center of mass of four 2 kg bodies placed at each corner of a square of side 1.5 m

Answer 1

Let the left bottom body be at the origin.

$$4mX=m(0+0+1.5+1.5)\\X=0.75\ m \\4mY=m(0+0+1.5+1.5)\\Y=0.75\ m\\$$

 COM is at center of square.