A long angle steel bar with 60 is inserted inside a large cylinder as shown below. The surface areas are A = 20 m, A = 10 m, A3 = 5 m, A4 = 5 m. The surface temperatures for A1, A2, A3, and A4 surfaces are T =25 C, T=300 C, T3=300 C, T4=300 C, respectively. Assume that the surfaces are blackbodies throughout the problem. F11 = F21 = F31 = F41 = 60 (a) Sketch a radiation heat transfer network circuit. Clearly denote each node and its temperature as well as the radiation thermal resistances between nodes. (b) Complete the following view factor matrix. Show your work in detail! F12 = F22 = F32= F42 = A3 F13 = F23= F33 = F43 = (c) Determine the heat flux from the surface A3 to A. F14= F24 F34= F44= =