Bernoulli's+Principle



Daniel Bernoulli was a Swiss scientist who said that the pressure of a moving fluid is different than the pressure of a fluid at that's notmoving. The principle says that the faster a fluid moves, the less pressure the fluid has. Bernoulli's principle helps explain how planes fly.It also helps explain why smoke rises in a chimney, how an atomizer works, and how a flying saucer glides through the air (Jones).Bernoulli was born in 1700 and came from a family of mathematitcians. During his lifetime Bernoulli lived in Italy and Russia. Bernoulli died at the age of 82 in 1782. (Irish University of Promoting Science)

Bernoulli's principle is in...

__Planes__ The Wright Brothers used Bernoulli's principle when they invented and designed the first airplane. Objects, like a plane, are designed so that the shape cause the air to move at different speeds. If the air moves faster above the object, fluid pressure pushes the object upward. If the air moves faster below the object, fluid pressure pushes it downward. The wing of the aiplane has a lift, or upward force to make it glide through the air. The same idea is enforced for the curve shape of a wing- it lifts. Because the top of the wing is curved, air moving at the top has a greater speed that air moving under the bottom. Then the air moving over the top exerts less pressure than the air below, creating a lift.



__Perfume Atomizers__ Bernoulli's principle is also in a perfume atomizer. When you're squeezing a perfume bottom with a rubber bulb used to squrit the perfume out, air moves quickly past the top of the tube. The moving air lowers the pressure at the top of the tube, the greater the pressure applied to the rubber ball, the more the perfume bottle pushes the liquid up into the tube where it comes out.



__Chimneys__ Smoke rises up the chimney because the hot air rises and is pushed out. Wind blowing across the chimney lowers the air pressure across the chimney. The higher the pressure at the bottom, the more smoke up the chimney. Also, the difference in air pressure between the top and bottom of teh chimney helps keep air moving upward (Jones).

__Flying Disks (Frisbees)__ When you are at the beach and you are throwing a frisbee, do you ever wonder how it just glides through the air? The upper surface of the disc is curved just like the wing of an airplane and since Bernoulli's Principle applies to airplane wings, it applies to frisbees. The faster-moving air follows the disc's curved upper surface and exerts less pressure then the slower air underneath. If you tilt the disc when you throw it, the air is pushed down and the air creates an equal and opposite force back onto the frisbee pushing and keeping it up. When you throw the disc (If it was thrown correctly!) it will spin and by spinning it keeps itself stable as it flies through the air.

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By: Leigh11 and megs06