How do i relate pressure drop with "h"? http://www.2shared.com/document/L4fH2kdT/HES_2340_Assignment_1.html 1. The problem statement, all variables and given/known data Hi, Regarding to the link above, I have a question on my homework on Q2 and Q4. In Q4, What pressure shall i consider in this situation? Shall i include the P,atm? I know there's 1.334N from top and shall i convert this to pressure? And related it to shear stress? For the velocity distribution. How do I use Navier-Stroke Equation on here to get the velocity diagram to see whether it's a laminar flow or turbulent flow. 2. Relevant equations Shear stress = viscosity x velocity profile Pressure = Force/Area 3. The attempt at a solution I want to sketch a velocity in Q2 and relate the pressure drop with clearance height,h includes the Length of cylinder and weight of piston.