Asteel tube [k 15 w/(m.°c)] of outside diameter 7.6 cm and thickness 1.3 cm is covered with an insulation material [k 0.2 w/(m. c)] of thickness 2 cm. a hot gas at 320°c with a heat transfer coefficient of 200 w/(m2.c) flows inside the tube. the outer surface of the insulation is exposed to cooler air at 20°c with a heat transfer coefficient of 50 w/(m2·°c). calculate a) the heat loss from the tube to the air for a 5-cm length of the tube. b) the temperature drops due to the thermal resistances of the hot gas flow, the steel tube, the insulation layer, and the outside air.