A long piece of wire with a mass of 0.1kg and a total length of 4m is used to make a square coil with a side of 0.1m. The coil is hinged along a horizontal side, carries a 3.4A current, and is placed in a vertical magnetic field with a magnitude of 0.01T. a) Determine the angle that the plane of the coil makes with the vertical when the coil is in equilibrium. For this part I was thinking, mg = F = BILcos phi, where phi is the angle with respect to the vertical... phi = arccos (mg/BIL) Now, I thought, "Which L can I use?" and I couldn't find the answer using different values.. can anyone please show me where I went wrong? b) Find the torque acting on t he coil due to the magnetic force at equilibrium. I'm guessing a) will give me what I need for this part. The answers are: a) 3.97deg b) 3.39 x 10^-3 Nm Thanks for any pointers!