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 soClick on Developer tab Click on Visual Basic Click on Insert tab Click on ModuleType your code into the module. The code should look something like