Section 3: Fluids and Motion
What You Will Learn:
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Describe the relationship between pressure and fluid speed.
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Analyze the roles of lift, thrust, and wing size in flight.
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Describe drag, and explain how it affects lift.
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Explain Pascal’s principle.
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Bernoulli's Principle:
In 1738, Swiss physicist Daniel Bernoulli discovered that as the speed of a fluid increases its pressure decreases. What does that mean? When air is still it pushes equally in all directions. For example, air pressure pushes down on a table, but also up on the underside. But when air moves along the surface of an object the pressure is reduced. A fan blowing across the
surface of the table reduces the downward pressure of air. A light wind has little effect on a heavy object like a table, but a slip of paper illustrates the principle well. Hold a strip of paper under your bottom lip and blow over it with fast stream of air. Your breath creates a low pressure pocket of air above the paper. Below the paper the air pressure is higher and it pushes the paper up.
(The above was taken from http://www.wowmuseum.com/documents/BITWTeachersGuide.pdf)
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