A 10-m-long pipe has an inside radius of 70 mm, an outside radius of 80 mm, and is made of stainless steel (k 5 15 W/ [m 8C]). Its inside surface is held at 1508C, and its outside surface is at 308C. There is no heat generation, and steady-state conditions hold. Compute the rate at which heat is being transferred across the pipe wall.

Along 8-cm diameter steam pipe whose external surface temperature is 900c connects two buildings. the pipe is exposed to ambient air at 70c with a wind speed of 50 km/hr blowing across the pipe. determine the heat loss from the pipe per unit length. (b) air at 500c enters a section of a rectangular duct (15 cm x 20 cm) at an average velocity of 7 m/s. if the walls of the duct are maintained at 100c. a) the length of the tube for an exit temperature of the air to be 40 0c. b)the rate of heat transfer from the air. c) the fan power needed to overcome the pressure drop in this section of the duct.