A conducting rod is pulled along horizontal, frictionless, conducting rails at a constant speed of 2.3m/s. The rails are spaced 82cm across. The entire system is in a uniform magnetic field of 0.018T that points into the screen. The resistance of the rod is 0.40Ω, but the resistance of the rails is negligible. What force must be applied to the rod in order to maintain the constant speed?

A conducting rod is pulled along horizontal, frictionless, conducting rails at a constant speed of 2.3m/s. The rails are spaced 82cm across. The entire system is in a uniform magnetic field of 0.018T that points into the screen. The resistance of the rod is 0.40Ω, but the resistance of the rails is negligible. What force must be applied to the rod in order to maintain the constant speed?