Two bodies of mass each hold an individual charge,  q1\displaystyle {q}_{{1}}  and q2\displaystyle {q}_{{2}} .  If they are separated by a distance r\displaystyle {r}  they will exert a force on each other,  FE\displaystyle {F}_{{E}} , due to Coulomb's Law.  What is the equation to solve for q2\displaystyle {q}_{{2}} in terms of these variables and any needed constants.

 q2\displaystyle {q}_{{2}}  =