[填空题]
(a) How much power is radiated by as/)5 kfa(*ojr-,)gsekl d c aoh/l lp* tungsteb dn(p ;v(lh7sc(l,uun sphere (emissivity ) of radius 22 cm at a temperature of 25 ? W
(b) If the sphere is enclosed in a room whose walls are kept at -5 what is the net flow rate of energy out of the sphere? W