Using the information in Problem 1.20, estimate the ambient air temperature that could cause frostbite on a

Question:

Using the information in Problem 1.20, estimate the ambient air temperature that could cause frostbite on a calm day on the ski slopes. From Problem 1.20Suppose that the inner temperature of a 3 mm thick layer of skin with a thermal conductivity of 0.35 W/(m K) is a temperature of 35?C. Under calm ambient conditions the heat transfer coefficient at the outer skin surface is about 20 W/(m2 K). Frostbite can occur when the skin temperature drops to about 10?C.GIVENSkier??s skin exposed to cold airSkin thickness (L) = 3 mm = 0.003 mInner surface temperature of skin (Tsi) = 35?CThermal conductivity of skin (k) = 0.35 W/(m K)Convective heat transfer coefficient in still air ( hc ) = 20 W/(m2 K)Frostbite occurs at an outer skin surface temperature (Tso) = 10?CASSUMPTIONSSteady state conditions prevailOne dimensional conduction occurs through the skinRadiative loss (or gain from sunshine) isnegligible