1. The problem statement, all variables and given/known data A charge (q) is placed in-between two other equal charges named Q. Q-----q-----Q a) If both Q's are positive, is charge q in equilibrium? If yes, is it a stable or unstable equilibrium? b) What about if one Q is negative while the other is positive? 3. The attempt at a solution a) I think the charge q will be in equilibrium, considering the attraction or repulsion forces will cancel out. However, I have no clue how to know if it is unstable or stable. b) q will not be in equilibrium, the forces will be in the same direction and thus not cancel out, giving q an acceleration.