Bernoulli Principle, 2nd try

[Tucker Hiatt <thiatt@USFCA.EDU>]

At 3:57 PM -0400 6/25/03, Wolfgang Rueckner wrote:
> My question is this -- can one make an argument about what the
> pressure difference ought to be from a molecular motion point of
> view?  And I'm not talking about a detailed kinetic theory of gases
> derivation but rather a plausible argument that could be used in an
> introductory physics course.

I appreciate your question very much, Wolfgang.  I am disappointed
that the answer seems, so far, to be "No; no one (on PHYS-L) *can*
explain Bernoulli's Principle from a molecular point of view."

I certainly wish I could do it.  Many of my introductory students
enjoy learning about the Bernoulli effect, and then are disappointed
when I am unable to explain it.  I am able to take a molecular point
of view in explaining other fluid phenomena (e.g., static pressure,
buoyancy, capillarity, and Pascal's Principle), but not Bernoulli's
Principle.

So, forgive me PHYS-Lers, but I must re-issue Wolfgang's question:
FROM A MOLECULAR POINT OF VIEW, WHY DOES FLUID PRESSURE VARY WITH
FLUID SPEED?

- Tucker