- #1

Dart82

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## Homework Statement

Two rigid rods are oriented parallel to each other and to the ground. The rods carry the same current in the same direction. The length of each rod is 0.70 m, while the mass of each is 0.071 kg. One rod is held in place above the ground, and the other floats beneath it at a distance of 8.2 10-3 m. Determine the current in the rods.

[URL=http://img53.imageshack.us/my.php?image=problem3ta5.gif][PLAIN]http://img53.imageshack.us/img53/5664/problem3ta5.th.gif[/URL][/PLAIN]

## Homework Equations

F = ILBsin(theta)

B = (uI)/(2 pi r)

## The Attempt at a Solution

i know that current will be the same for both rods and since the current is flowing in the same direction, the magnetic force will be attractive between the rods. i know the length of each wire and the mass. i don't know how to progress in this problem because it seems to me that i need to know the magnetic field to be able to solve either equation. is there a way to solve this problem without knowing the magnetic field or am i overlooking something here? I'm stumped.