Answer:
Nup = 8
Step-by-step explanation:
u(r) = C1 and T(r) = T(s) = C2 [ 1 - r/ro)^2 ]
The temperature and velocity particles at a particular axial location is Uniform and parabolic
The Nusset Number Nup at this location can be obtained by first determining/calculating for the convection coefficient =

Therefore the mean temperature is calculated as follows
attached is the detailed solution and free body diagram