The density of charge-carrying electrons in copper is 8.5 × 1028 electrons m?3, its resistivity is 1.72 × 10-8 ?·m, and the drift speed is 2.80 × 10-3 m/s. The wire has a diameter of 1.20 mm and a length of 1.60 m. At what rate must thermal energy be carried off by a cooling medium if the wire is to maintain its temperature?