A heating element in the shape of a cylinder is maintained at 2000°F and placed at the

Question:

A heating element in the shape of a cylinder is maintained at 2000°F and placed at the center of a half-cylindrical reflector as shown. The rod diameter is 2 in. and that of the reflector is 18 in. The emissivity of the heater surface is 0.8, and the entire assembly is placed in a room maintained at 70°F. What is the radiant energy loss from the heater per foot of length? How does this compare to the loss from the heater without the reflector present? A heating element in the shape of a cylinder is