# Bernoulli's principle

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Related to Bernoulli's principle: Pascal's principle, Bernoulli's equation

## Bernoulli's principle,

physical principle formulated by Daniel Bernoulli that states that as the speed of a moving fluid (liquid or gas) increases, the pressure within the fluid decreases. The phenomenon described by Bernoulli's principle has many practical applications; it is employed in the carburetor and the atomizer, in which air is the moving fluid, and in the aspirator, in which water is the moving fluid. In the first two devices air moving through a tube passes through a constriction, which causes an increase in speed and a corresponding reduction in pressure. As a result, liquid is forced up into the air stream (through a narrow tube that leads from the body of the liquid to the constriction) by the greater atmospheric pressure on the surface of the liquid. In the aspirator air is drawn into a stream of water as the water flows through a constriction. Bernoulli's principle can be explained in terms of the law of conservation of energy (see conservation lawsconservation laws,
in physics, basic laws that together determine which processes can or cannot occur in nature; each law maintains that the total value of the quantity governed by that law, e.g., mass or energy, remains unchanged during physical processes.
, in physics). As a fluid moves from a wider pipe into a narrower pipe or a constriction, a corresponding volume must move a greater distance forward in the narrower pipe and thus have a greater speed. At the same time, the work done by corresponding volumes in the wider and narrower pipes will be expressed by the product of the pressure and the volume. Since the speed is greater in the narrower pipe, the kinetic energy of that volume is greater. Then, by the law of conservation of energy, this increase in kinetic energy must be balanced by a decrease in the pressure-volume product, or, since the volumes are equal, by a decrease in pressure.

## Bernoulli's principle

An increase in the velocity of a fluid that is accompanied by a decrease of pressure. Swiss scientist, Daniel Bernoulli (1700-1782), demonstrated that, in most cases, the pressure in a liquid or gas decreases as the liquid or gas moves faster. This explains in part why a wing lifts an airplane.

The Lift of a Wing The curved top of a wing creates a longer distance from front to back than the straight bottom. This causes the air on top to travel farther, and thus faster, to reach the back than the air underneath, creating a difference in pressure between the two surfaces.
References in periodicals archive ?
Common misconceptions and challenges associated with understanding Bernoulli's principle
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Although pressure forms the basis for understanding topics such as the internal structure of the earth, weather cycles, rock formation, Bernoulli's principle, and plate tectonics, the presence of this concept in the school curriculum is at a minimal level.
Boy, he would have been really nervous during my science magic show, if he had seen me put a piece of paper I had set on fire in a bottle to illustrate Bernoulli's Principle.
For example, the gaseous lead will be cooled quickly after ejection due to the venturi effect, or Bernoulli's principle.
Vinturi applies Bernoulli's principle, which states that as the speed of a moving fluid increases, the pressure within the fluid decreases.
Bernoulli's Principle states that a decrease in pressure occurs as the speed of a fluid increases.
To illustrate Bernoulli's Principle and help students better understand how the shape of a wing can provide lift, I give my students two strips of paper (2.
His style is witty, and his presentation is thoughtful, as he clearly explains refraction, the Doppler shift, and Bernoulli's principle.

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