A spherical Pyrex glass shell had inside and outside diameters of D1=0.1m and D2= .2m, respectively. The inner surface is at Ts,1= 100 C while the outer surface is at Ts,2= 45 C.
a) Determine the temperature at the midpoint of the shell thickness, T(r=.075m).
b) For the same surfaces temperatures and dimensions as in part (a), show how the midpoint temperature would change if the shell material were aluminum.