Lesson 5, part 2: solving Navier-Stokes for pipe flow

This second part of lesson 5 examines the same problem as the first part of lesson 5, but solves the Navier-Stokes equations to arrive at the velocity field rather than using a force balance.

[andrewmountianou]

Very helpful.

I did the homework and it was impossible unless, I add an extra minus on the ΔP/L, but need to justify physically.