Question: Hot water is flowing at an average velocity of 4 ft/s through a cast iron pipe (k = 30 Btu/h.ft.°F) whose inner and outer diameters are 1.0 in and 1.2 in, respectively. The pipe passes through a 50-ft-long section of a basement whose temperature is 60°F. The emissivity of the outer surface of the pipe is 0.5, and the walls of the basement are also at about 60°F. If the inlet temperature of the water is 150°F and the heat transfer coefficient on the inner surface of the pipe is 30 Btu/h.ft2.°F, determine the temperature drop of water as it passes through the basement. Evaluate air properties at a film temperature of 105°C and 1 atm pressure. Is this a good assumption?