Balancing four point charges so that the net force acting on each charge is 0.

[haldavidc]

Homework Statement

Find positions of four charges in a plane (+1C, -1C, +2C, -2C) that result in an equilibrium (zero net force on each charge). Report positions as four (x,y) pairs.

Homework Equations

F = $$\frac{k_{e}q_{1}q_{2}}{r^{2}}$$

The Attempt at a Solution

I had no idea where to start. It seemed to me that regardless of where I put the charges there would be a net force.

 

[Phrak]

In your equation of the force between two charges, when does the force tend toward zero?