What is the Direction of the Magnetic Field Needed to Levitate a Copper Rod?

[matt72lsu]

Homework Statement

A 0.49 m copper rod with a mass of 0.13 kg carries a current of 10 A in the positive x direction. Let upward be the positive y direction.
1) What is the magnitude of the minimum magnetic field needed to levitate the rod?
2) What is the direction of the minimum magnetic field needed to levitate the rod?
pos x direction, neg x, pos y, neg y, pos z, neg z

Homework Equations

Right Hand Rule?

The Attempt at a Solution

I figured out part 1 but not sure on part two. any guidance would be appreciated. I'm thinking it's positive y direction. Part 1 answer was B = .26 T fwiw

 

[kodadra]

Yup, simply use the right hand rule. You know the current is going to the right (positive x) and to levitate the rod you would need a force going up (positive y). So by using the right hand rule you should be able to find the direction of the magnetic field.