• # question_answer Three equal mass (m) are placed at vertex of an equilateral triangle of side r. work required to double the separation between masses will be:                   A)  $\frac{G{{m}^{2}}}{r}$B)  $\frac{3G{{m}^{2}}}{r}$C)  $\frac{3}{2}\frac{G{{m}^{2}}}{r}$D)  None

work done = change in Gravitational potential Energy $W={{U}_{F}}-{{U}_{I}}$ $=3\left( \frac{-G{{m}^{2}}}{2r} \right)-\left( \frac{-3G{{m}^{2}}}{r} \right)$ $=\frac{3}{2}\frac{G{{m}^{2}}}{r}$