The spectral emissivity function of an opaque surface at 1000 K is approximated as 5.55 points €1 = 0.4,0 um <<3 um Ej = €2 = 0.7, 3 um << 6 um ε3 = 0.3, 6 μm <λ<0 Skipped Determine the average emissivity of the surface and the rate of radiation emission from the surface, in kW/m2. References The average emissivity of the surface is The emissive power of the surface is kW/m2.