What Current Prevents the Cylinder from Rolling Down the Inclined Plane?

[carah90]

Homework Statement

The figure shows a tree cylinder of mass m = 0.250 kg and length L = 0.100 m. In a plane containing the cylinder axis of symmetry a conducting wire has been longitudinally wrapped 10.0 times around the cylinder. The cylinder is released along an inclined plane (angle θ), so that the plane formed by the wire coil is parallel to the inclined plane. How much current(I) should go through the wire so that the cylinder does not begin to roll down the plane, if a vertical magnetic field B = 0.500 T intersect with the inclined plane?

Here's a link to the figure: https://lh3.googleusercontent.com/_Z0fi2BqoS24/TVFxISWgGbI/AAAAAAAAAuY/U3-f2ua1Fnc/Picture%201.png

Homework Equations

The Attempt at a Solution

I don't know where to begin. Maybe using Biot-Savart's law?
Thanks in advance:)

 

[gneill]

Think torque.

 

[carah90]

okey. thanx. will give it a try.