QUESTION 3: (12 Marks) Calculate the rate of heat loss per unit area from a thermo flask if the polished silvered surfaces have emissivities of 0.05, the liquid in the flask is at 368K and the casing is at 293K. Determine the rate of heat loss per unit area if both the surfaces were black. Data: Stefan-Boltzmann constant σ = 5.67 × 108 W/(m².K4) The rate of heat loss per unit area is given by Q/A = σ (T1 – T2) / [(1/1) + (A1/A2){(1/ ε2) - 1}] Where A area of the inner cylinder A2 area of the outer cylinder (12 Marks)