Problem 5.252

There are two cavities (Fig. 5.39) with small holes of equal diameters \(d=1.0 \mathrm{~cm}\) and perfectly reflecting outer surfaces. The distance between the holes is \(l=10 \mathrm{~cm}\). A constant temperature \(T_{1}=1700 \mathrm{~K}\) is maintained in cavity \(1 .\) Calculate the steady-state temperature inside cavity 2 .

Instruction. Take into account that a black body radiation obeys the cosine emission law.