An annular aluminum fin of rectangular profile is attached to a circular tube having an outside diameter of 25 mm and a surface temperature of 250°C. The fin is 1 mm thick and 16 mm long, and the temperature and the convection coefficient associated with the adjoining fluid are 25°C and 25 W/m2·K, respectively. Evaluate the properties of aluminum at 400 K. (a) What is the heat loss per fin? (b) If 200 such fins are spaced at 5-mm increments along the tube length, what is the heat loss per meter of tube length?