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## Homework Statement

Two flexible but not extensible strings with linear charge density s and length L are attached to two insulating balls a distance D apart, where D<L. What do the strings look like when the system is at equilibrium?

## Homework Equations

## The Attempt at a Solution

I think that the strings will look like two circular arcs, but I am not sure about that. I was thinking that they would lie on the equipotential lines as if the distance D was itself a line charge, but I don't know why. Is it true that the tension in the string would have to balance out the es force at each string element? I was wondering if writing the lagrangian for the problem and integrating would help, but I want to know if anyone has any insight as to how to tackle this using some nifty "trick" based on symmetry or something. Thanks.