3.61 Steam flowing through a long, thin-walled pipe main- tains the pipe wall at a uniform temperature of 600 K. The pipe is covered with an insulation blanket comprised of two different materials, A and B. The interface between the two materials may be assumed to have an infinite contact resistance, and the entire outer surface is exposed to air for which T.. = 320 K and h = 25 W/m.K. A - = 60 mm r2 = 120 mm = T,,21A) KA = 2 W/m.K T, 28) kg = 0.25 W/mK T.1 = 600 K Toh B (a) Sketch the thermal circuit of the system. Label (using the preceding symbols) all pertinent nodes and resistances. (b) For the prescribed conditions, what is the total heat loss from the pipe? What are the outer surface tem- peratures T..2(a) and T.2(B)