Ask A Scientist© Physics Archive

name         Richard
status       student
age          20s

Question -   Could you please tell me the relationship between a
gas/liquid, it's viscosity and velocity, and the pressure it exerts upon
a surface.  I.e. water flowing down a pipe with no turbulence will exert
more force the faster it travels.  Is there an equation to represent this
and could you please explain it to me.
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Bernoulli's equation.  Look in any fluid mechanics book and you'll find
Bernoulli's equation and what it represents.  Basically, Bernoulli's
equation states that a fluid flowing through a pipe has both kinetic energy
(energy due to its motion (velocity)) and potential energy (energy stored
due to its position and composition (density)).  If one of the energy forms
increases, the other must decrease in order to conserve energy.  A few
things to note about fluid flow:
1. a fluid flows due to a difference in pressure
2. a resistance to flow creates pressure
3. viscosity is measure of how a fluid resists flow (see note 2).
Hope this helped.

C. Murphy
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Although I do not have any formulas for you, your question relates to
Bernoulli's principle.  As the velocity of a fluid increases, its pressure will
decrease.  You might wish to hit the reference books and pursue this principle.

Larry Krengel
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