Four particles each of mass `m` are kept at the four vertices of a square of side 'a' . Find gravitational potential energy of this system.

Explanation

`F_(R)=sqrt(2)F+F.=(sqrt(2)Gm^(2))/(a^(2))+(Gm^(2))/(2a^(2))`
`F_(R)=(Gm^(2))/(a^(2))(sqrt(2)+1/2)` along the diagonal towards the opposite corner.