1. The problem statement, all variables and given/known data Suppose the rod in the figure below has mass m = 0.375 kg and length 18.5 cm and the current through it is I = 36.2 A. http://img183.imageshack.us/img183/2059/dgian2757.gif [Broken] If the coefficient of static friction is mus = 0.503, determine the minimum magnetic field B (not necessarily vertical) that will just cause the rod to slide. Give the magnitude of B and its direction (angle) relative to the vertical. 2. Relevant equations |F|=I*l*B*sin(theta) Ff=Fn*mus Fn=m*g 3. The attempt at a solution Fn=3.67875 N Ff=1.85 N The magnetic force needs to be strong enough to overcome Ff, so Ff=I*l*B*sin(theta). Surely that force is maximised when sin theta is one, so relative to the vertical that angle must be 0? Thus, 1.85=36.2*(18.5/100)*B, so B= .276 T, at an angle of 0 deg relative to the horizontal, however this is incorrect. At what point am I going wrong?