Q 11-07-033NEETJEE MainMedium
Three particles, each of mass $m$, are placed at the vertices of an equilateral triangle of side $a$. The gravitational potential energy of the system is
Answer: (A) $-\dfrac{3Gm^2}{a}$
There are three pairs, each separated by $a$:
$$U = 3\left(-\frac{Gm^2}{a}\right) = -\frac{3Gm^2}{a}$$
Solution by Sreeraj P, M.Sc Physics