Ok, so it's just the drag from the pipe wall then? That makes sense.
I got hung up thinking about if you have a certain force pushing an amount of fluid through at a time, the same comes out at the other end, regardless of how far away that end is.
But it makes sense if drag is the only thing...
I can't figure out why the length the a pipe (L) increases the change in driving pressure with respect to this law:
Delta P = (8*mu*L*Q)/(pi*(r^4))
I would think that delta P wouldn't change because the fluid is incompressible.
Does anyone have a conceptual explanation for the simple...