Three equal charges at the vertices of an equilateral triangle. Net force on each charge is $F\hat{r

Question

Three equal charges at the vertices of an equilateral triangle. Net force on each charge is $F\hat{r}$. Then sum of forces on all the charges is

Professor PC Thomas Classes · Answer

The sum of forces on all the charges is zero because forces are internal to the system. This is an application of Newton's third law.