It is one-dimensional, and nothing to overthink I believe. It's a first-year intro course so nothing too complicated.
The issue is the criterion wasn't provided, so I'm trying to determine this on my own.
Homework Statement
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...