An enclosure has an inside area of 50 m2, and its inside surface is black and is maintained at a constant temperature. A small opening in the enclosure has an area of 0.01 m2. The radiant power emitted from this opening is 48 W. What is the temperature of the interior enclosure wall, in K

Ahair dryer is basically a duct in which a few layers of electric resistors are placed. a small fan pulls the air in and forces it through the resistors where it is heated. air enters a 1200 w hair dryer at 100 kpa and 22°c and leaves at 47°c. the cross-sectional area of the hair dryer at the exit is 60 cm2. neglecting the power consumed by the fan and the heat losses through the walls of the hair dryer, determine (a) the volume flow rate of air at the inlet and (b) the velocity of the air at the exit.