A small surface of area A1 = 8 cm2 emits radiation as a blackbody at T1 = 800 K. Part of t...

A small surface of area A1 = 8 cm2 emits radiation as a blackbody at T1 = 800 K. Part of the radiation emitted by A1 strikes another small surface of area A2 = 8 cm2 oriented as shown in the figure. Determine the solid angle subtended by A2 when viewed from A1, and the rate at which radiation emitted by A1 strikes A2 directly. What would your answer be if A2 were directly above A1 at a distance of 80 cm?

FIGURE P12-49