I was just unsure as to whether the velocities were being measured in the frame of the fluid velocity or a rest flame, since it was not stated in my notes, but your first comment made me realize that it was as measured traveling with the fluid, so I think I get that now thanks.
But for future...
Yes sorry-perhaps this is not so related to fluid dynamics-it isn't in my lecture notes but it just seemed to keep coming up whenever I looked up pressure!
Thanks! I think I understand the concept now in terms of kinetic theory, like this https://en.wikipedia.org/wiki/Kinetic_theory_of_gases#Pressure_and_kinetic_energy , but I'm having trouble squaring this with the equation rho*g*h often given for the pressure in a liquid at depth h: the second...
I'm studying fluid dynamics and we just had a lecture about the momentum equation. We started the lecture by talking about pressure in terms of molecules moving across a hypothetical surface element and carrying their momentum with them (in both directions). There are 2 things confusing me about...