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A wall panel is insulated on the back and exposed to solar radiation on the front...

A wall panel is insulated on the back and exposed to solar radiation on the front surface. The exposed surface of the plate has an absorptivity α = 0.8 for radiation (i.e. 80% of radiant energy is absorbed). Solar radiation arrives to the panel at a rate of 1 kW⁄m2. The panel emissivity ϵ = 1 and the surrounding air temperature is 25°C.

a. If we assume radiation is the only mechanism of heat transfer, in this scenario determine the equilibrium surface temperature (˚C) of the panel. Note that equilibrium requires the rate of heat transfer by radiation outward equal the total rate of heat transfer by radiation inward (sum of radiation from the sun and the surrounding air).

b. If we assume convection is the only mechanism of heat transfer, in this scenario find the equilibrium surface temperature (˚C) of the panel using a convective heat transfer coefficient ℎ = 20W⁄m2·K. FE-

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