Ex-6 1005 500% 200 Consider steady heat transfer between two large parallel plates at constant temperatures of Ti 300 K and T 200 K that are L 1 cm apart, as shown in Fig. 16-20. Assuming the surfaces to be black (emissivity s 1), determine the rate of heat transfer between the plates per unit surface area assuming the gap between the plates is (a) filled with atmospheric air, (b) evacuated, (c) filled with urethane insulation, and (o) filled with superinsulation that has an appar- ent thermal conductivity of 0.00002 W/m . C. 7 = 300 K T., = 260 K 330 K 20% K 300 K 2000 300X 200 K 300 K 380K Q=87 W Q=36x W } ca ECO (a: air souce 0-269W ton 2-02W (c) lasuiation Superinatacios 26 20