A conductor bar with mass m and length L slides over horizontal rails that are connected

A conductor bar with mass m and length L slides over horizontal rails that are connected to a voltage source. The voltage source maintains a constant current I in the rails and bar, and constant, uniform, vertical magnetic field `vecB` fills the region between the rails (as shown in Fig.) Find the magnitude and direction of the net force on the conducting bar. Ignore friction, air resistance and electrical resistance.