A copper rod of uniform circular cross section connects two large thermal reservoirs. One reservoir is maintained at 150∘C and the other at 30∘C. The rod is 0.45m long and has a diameter of 1.2cm. The thermal conductivity of copper can be taken as 390Wm−1∘C−1 over the temperature range involved.
(a) Calculate the rate at which thermal energy is conducted through the rod when steady-state conditions have been reached.
(b) Determine the total thermal energy transferred from the hot reservoir to the cold reservoir during a 10min interval.
(c) Interpret your result in part (b) in everyday terms by identifying an electrical appliance that would consume approximately the same amount of energy in 10min. Justify your identification with an order-of-magnitude comparison.