Maybe my misunderstanding is how the speed would be independent of torque. My thought was that the 2x resistor has 2x the coefficient of kinetic friction, whic

Maybe my misunderstanding is how the speed would be independent of torque. My thought was that the 2x resistor has 2x the coefficient of kinetic friction, which means 2x force and 2x frictional torque. In order for the system to be at equilibrium, meaning constant speed, the battery torque must match the friction torque.