NCERT Example 7.3 - Gravitation
Question: Find the gravitational potential energy of four equal masses m at the corners of a square of side l and the potential at the square centre.
Answer: U = **-(Gm²/l)(4+sqrt2)**; V_c = **-4sqrt2 Gm/l**.
Full step-by-step NCERT solution with diagrams on Something by Zero.