Combined heat flow - Tin=900K A Furnace wall consists of a 1.2cm steel wall exposed to air with temperature of 300K(L1) and 5cm of insulation exposed to the furnace temperature of 900K(L2). Heat transfer coefficient is 10W/m2K on the inside, and 15 W/m2K on the outside. Assume steady state - with k1=19W/mK and k2=0.7W/mK. a. Determine the heat flux through the wall b. Determine the temperatures of the interface (Ti) as well as the surface temperatures of the steel and insulation (T1 and T2 )