Magnetic force, coefficient of friction, forces in equilibrium

[wushumaster]

A 1.0 kg copper rod rests on two horizontal rails 1.0 m apart and carries a current of 50 A from one rail to the other. The coefficient of static friction between rod and rails is 0.60. What are the (a) Magnitude and
(b) Angle (relative to the vertical) of the smallest magnetic field that puts the rod on the verge of sliding?

I can get what B times sin theta is by setting mu times mg = iLBsin theta, but how to get B or theta?

 

[Redbelly98]

A 1.0 kg copper rod rests on two horizontal rails 1.0 m apart and carries a current of 50 A from one rail to the other. The coefficient of static friction between rod and rails is 0.60. What are the (a) Magnitude and
(b) Angle (relative to the vertical) of the smallest magnetic field that puts the rod on the verge of sliding?

I can get what B times sin theta is by setting mu times mg = iLBsin theta, but how to get B or theta?

Before we go farther with this, I don't think this equation is correct. Have you drawn a free-body or force diagram for the rod? Since it can be difficult to post a figure here, I'll just ask you to list here all the forces acting on the rod -- and you should still draw a force diagram for yourself.