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= = Question 1 (7.5 Marks) A triangular baking oven as shown in Figure 10L = L1 = L2 = L3 = 1m) has a heated bottom surface a (surface 1) at 1200K, side surface (surface 2) at 500K whereas the other side surface (surface 3) is insulated (reradiating surface). The emissivities of surfaces 1 and 2 are 0.8 and 0.4, respectively. Calculate the total rate of energy by radiation a) from the bottom surface to the uninsulated side surface. b) from the bottom surface if surface 3 is not insulated and is at 500K and having an emissivity of 0.4. L2