A 15.0-g conducting rod of length 1.30 m is free to slide downward between two vertical rails without friction. The ends of the rod maintain electrical contact with the rails. The rails are connected to a 4.80-Ω resistor, and the entire apparatus is placed in a 0.390-T uniform magnetic field. Ignore the resistance of the rod and rails.

(a) What is the terminal velocity of the rod?
(b) At this terminal velocity, compare the rate of change of the gravitational potential energy with the power dissipate in the resistor.