Consider a cylindrical cavity of diameter D=100 mm and depth L=50 mm whose sidewall and bottom are diffuse and gray with an emissivity of .6 and are at a uniform temperature of 1500 K. The top of the cavity is open and exposed to surrounding that are large and T=300K. a) Calculate the net radiation heat transfer from the cavity, treating the bottom and sidewall of the cavity as one surface (qa). b) Repeat a treating the bottom and the sidewall as two surfaces (qb) c) Plot the percent difference between qa and qb as a function of L as L ranges from 5 to 100 mm.