A steal pipe (inside radius of 0.5245 in and outside radius of 0.6575 in) carries saturated steam at 250F. The pipe is insulated with a 2-in layer of 85 percent magnesia pipe covering, and outside this magnesia there is a -inch layer of cork. The inside temperature of the pipe wall is 249F, and the outside temperature of the cork is 90 F. Thermal conductivities (Btu/ft.h.F) are: for steel, 26; for magnesia, 0.034; for cork, 0.03. a) Calculate the logarithmic mean radius () for each layer (in). b) Calculate the individual resistance of each layer (F.h/Btu) in 100 ft of pipe