A 12.0-g conducting rod of length 1.30 m is free to slide
downward between two vertical rails without friction. The rails
are connected to an 8.00 ? resistor, and the entire apparatus is
placed in a 0.340 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, calculate
the rate of change in gravitational potential energy (include
sign) and the power dissipated in the resistor.  Want an answer?