A rod of mass m = kg and radius r = m rests on two parallel rails (Fig. P29.37) that are d = m apart and l = m long. The rod carries a

current of i = A in the direction shown and rolls along the rails without slipping. A uniform magnetic field of magnitude b = T is directed perpendicular to the rod and the rails. If it starts from rest, what is the speed of the rod as it leaves the rails?