The figure below shows a bar of mass m = 0.260 kg that can slide without friction on a pair of rails separated by a distance = 1.20 m and located on an inclined plane that makes an angle ? = 29.0° with respect to the ground. The resistance of the resistor is R = 1.20 ? and a uniform magnetic field of magnitude B = 0.500 T is directed downward, perpendicular to the ground, over the entire region through which the bar moves. With what constant speed v does the bar slide along the rails?