Two plates, one with a black painted surface and the other with a special coating (chemically oxidized copper) are in earth orbit and are exposed to solar radiation. The solar rays make an angle of 30° with the normal to the plate. Estimate the equilibrium temperature of each plate assuming they are diffuse and that the solar flux is 1368 W/m2. The spectral absorptivity of the black painted surface can be approximated by aA = 0.95 for 0 A 00 and that of the special coating by aA = 0.95 for 0 A 3 µ,m and aA = 0.05 for A > 3 µ,m.