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Homework Help: Conceptual questions in Fluid Mechanics

  1. Oct 15, 2008 #1
    1. The problem statement, all variables and given/known data
    Define:Static pressure
    Dynamic Pressure
    Continuum hypothesis
    Kinetic Viscosity
    Kinematic Viscosity

    2. The attempt at a solution

    The real question is : are these answers sufficient?

    Static Pressure
    - The pressure exerted by a fluid on an object placed within the fluid is called the static pressure.

    Dynamic Pressure - The pressure exerted by a fluid on an object that is moving through the fluid. This is given by:
    [tex] q = \frac{1}{2} \rho v^2 [/tex]

    I get the feeling that this is wrong...

    Continuum hypothesis - the region to be described can be subdivided into a set of (infinitesimal) volume elements, each of which simultaneously:
    1) is small enough to be considered uniform (i.e. any spatial variations in properties -- such as r, v,T, p -- inside the volume element are negligible); and
    2) is large enough to contain a statistically large number of molecules.

    Kinetic Viscosity - I think he means dynamic viscosity
    The definition for dynamic viscosity is the force per unit area a liquid exerts on two parallel plates that enclose the liquid. I would be more concise with this explanation when i'm writing it out that is, i will give an example.

    Kinematic Viscosity - The ratio of the dynamic viscosity and the density of the fluid.

    I am not sure about the last two definitions, i think they are too short. However i have looked through a few textbooks - Lifsitz/Landau, Houghton/Carpenter (my course text), Batchelor, but none of them have yielded a satisfactory answer for the last two definitions.
    I would really appreciate your help!

    Thank you
     
  2. jcsd
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