1. The problem statement, all variables and given/known data The figure shows a cylinder of mass 3.5kg, radius 4.4cm and length 10.2cm with 105turns of wire wrapped around it lengthwise, so that the plane of the wire loop contains the axis of the cylinder. What is the least current which while flowing through the loop will prevent the cylinder from rolling down an inclined plane of inclination 21°, in the presence of a vertical magnetic field of B=0.7T? The plane of the windings is parallel to the inclined plane. m = 3.5 kg r = 4.4cm = 0.044m l = 10.2cm = 0.102m theta = 21degrees B = 0.7T n = 105 turns I = ? 2. Relevant equations Magnetic torque = (n/l)IABsin(theta) Gravitational torque = r x F = mgrsin(theta) Torque_CW - Torque_CCW = 0 3. The attempt at a solution Okay so I know that the sum of the torques must be zero, and that there will be a torque from gravity and one from the magnetic field, but I'm confused as to how to actually set up the equations. For gravity I tried doing a free body diagram but I didn't know where to consider gravity to be acting on. And for the magnetic torque I have the equation, but from looking at the picture I would assume that the CW and CCW torques due to magnetism would be equal and impossible to balance with gravity. I think my main problem with this question is coordinates.