A spherical Pyrex glass shell has inside and outside diameters of D = 0.15 m and D2 = 0.30 m, respectively. The inner surface is at Ts, = 120C while the outer sur- face is at T2 = 60C. (a) Determine the temperature at the midpoint of the shell thickness, T(r = 0.1125 m). (b) For the same surface temperatures and dimensions as in part (a), show how the midpoint temperature would change if the shell material were aluminum