Create a Visual Basic function that calculates the Darcy$-$Weisbach friction

factor using the Churchill equation. Call the function ffactor$($Re$,$rr$)$

where

Re $=$ Reynolds number

rr $=$ the relative roughness.

Do not turn your code into an add$-$in that works only on your machine.

The friction factor function must be part of the workbooks you submit. To do so

Click on Developer tab Click on Visual Basic Click on Insert tab Click on Module

Type your code into the module. The code should look something like

Function ffactor$($Re$,$rr$)$ A$=...$

B$=...$

ffactor $=.......$

End Function

Save the workbook as a type "Excel Macro$-$Enabled Workbook". Use this workbook as the starter on su