1. (a) An enclosure has an inside area of 100 m2, and its inside surface is black and is maintained at a constant temperature. A small opening in the enclosure has an area of 0.02 m2. The radiant power emitted from this opening is 70 W. What is the temperature of the interior enclosure wall? 70 W 0.02 m2 (b) If the interior surface temperature is maintained as in (a), but the surface is gray with emissivity, 0.79, what is the radiant power emitted from the surface?