Answer:

Step-by-step explanation:
Our data given are:
Mean temperature (inlet)
D = Diameter
L = Length
Mass flow rate
Equation to surface flow as,

We need to consider the perimeter of tube (p) to apply the steady flow energy balance to a tube , that is

Where

Re-arrange for


Integrating from 0 to x (the distance intelt of pipe) we have,

Replacing the value of q(x)



