Chapter 13, Problem 13.87P

Two convex objects are inside a large vacuum enclosure whose walls are maintained at $T_3=300\text{K}$ . The objects have the same area, $0.2{\text{m}}^{\text{2}}$ , and the same emissivity, 0.2. The view factor from object 1 to object 2 is $F_{12}=0.3$ . Embedded in object 2 is a heater that generates 400 W. The temperature of object 1 is maintained a $T_1=200\text{K}$ by circulating a fluid through channels machined into it. At what rate must heat be supplied (or removed) by the fluid to maintain the desired temperature of object 1? What is the temperature of object 2?