The surface also exchanges heat with the surrounding walls of the enclosure by radiation. the total hemispherical emissivity of the surface is 0.9. the surface is completely surrounded so the surface behaves as if each portion of it interacts with a blackbody at the temperature of the enclosure walls. properties of the air are: k = 0.0261 w/mk, € ν =1.8 ×10−5 m 2 /s, pr = 0.73 and the stephan-boltzmann constant is € 5.67 ×10−8 w/m2 k4 . (a) determine the total heat flux from the surface at a location 4.5 cm from the lower edge. (b) sketch the variation of surface heat flux q” with x. (c) where is the absolute value of the surface heat flux smallest? (d) for this system, what is the asymptotic dependence of heat flux on x as the distance from the bottom becomes large?