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A wall is constructed of composite layers with overall thickness L = 50 cm and a height H 60 cm. Sections A and B each have height 30 cm and thickness 30 cm. The thermal conductivity of sections A, B and C are k = 1 W/m K, kB = 2 W/m K and = kc = 0.5 W/mK, respectively. The top and bottom of the wall are insulated. The interior and exterior air temperatures are Too,i = 22C and To,o=0C, respectively. The inner and outer convection heat transfer coefficients are h = 5 W/m. K and ho = 30 W/m.K, respectively. Determine the heat rate per unit wall depth T. 0C h, -30 W/mK L A B . H T-22C h-5 W/m K