Turbulent friction coefficient over a plate

[pressurised]

Homework Statement

Homework Equations

C_f=0.0577(μ/xρU_m)^0.2

The Attempt at a Solution

I've managed to do parts a) and b), however I don't believe my attempt at the first part is correct as I am using a different C_f than the value used in the mark scheme.

The expression I made for the first part is, 0.0577(μ/ρU_m)^0.2[x^0.8], with limits L and 0.
This gave me a C_Df of 0.00421, but it should be 0.00263.

 

[TSny]

I don't know anything about this. But look at the bottom of page 5 here
www.eng.auburn.edu/~tplacek/courses/2610/samba/CHEN2610FacultyCh7a.doc

You can see a comment stating that C_D is an integrated average of the local C_f over the surface area. So, you still need to do something after you integrate C_f over the area.