# Parallel wire repulsive force

1. Oct 8, 2010

### cdotter

1. The problem statement, all variables and given/known data

[PLAIN]http://img813.imageshack.us/img813/6592/36756643.png [Broken]

2. Relevant equations

$$F=\mu_0\frac{II'L}{2\pi r}$$

3. The attempt at a solution

The wires have a weight $$\lambda Lg$$. They require an equal but opposite force to keep them at equilibrium at 6.00 degrees. This force comes from the repulsion between the oppositely flowing currents in the wires, given by
$$F=\mu_0\frac{I^2L}{2\pi r}$$. The distance r between the two wires is $$sin(6.00 degrees)*0.0400 m*2$$.

I'm stuck at the components of the forces. Could someone give me a hint? I'm terrible at geometry.

Last edited by a moderator: May 5, 2017
2. Oct 9, 2010

### tiny-tim

hi cdotter!
hint: call the tension in each string T,

and do components of forces in the y and x directions

3. Oct 10, 2010

### cdotter

Got it, thank you.