Pascal's law
Pressure change in a confined fluid is transmitted equally everywhere.
Last updated
The NASA resource describes it as an equal increase in pressure at every other point in the container when pressure increases at one point.[1] The HyperPhysics site notes that pressure is transmitted undiminished in an enclosed static fluid.[2] In a confined incompressible fluid, any alteration in pressure at one location results in an identical alteration throughout the entire fluid, according to Pascal's law.[3][1][2]
Quick Facts
- Field
- Fluid mechanics
- Nationality
- French
- Known for
- Pascal's law (principle of transmission of fluid-pressure)
Facts from the source article.
Key facts and history
The experiment is not mentioned in Pascal's preserved works and may be apocryphal, attributed by 19th-century French authors.[4] Blaise Pascal, a French mathematician, formulated this principle in 1653, with the work appearing in print in 1663.[3] A long vertical tube was reportedly inserted into a sealed water barrel during a hydrostatics demonstration known as Pascal's barrel.[5] The barrel supposedly ruptured due to the rising hydrostatic pressure as water was added to the tube.[5]
When both inertia and viscosity are omitted from the Navier–Stokes equations, the resulting formula matches this principle.[6] Most motor vehicles use this principle to amplify force within their braking systems.[7] Artesian wells, water towers, and dams are examples of structures that apply this principle.[7] For scuba divers, grasping this principle is essential to manage pressure variations with depth.[7]
What the cited sources add
The NASA resource states that Pascal's law allows forces to be multiplied in a hydraulic car lift.[1] The HyperPhysics site explains that a hydraulic press multiplies force by using different piston areas, allowing a heavy load to be lifted with a small force.[2] For an ideal hydraulic press, the work input must equal the work output, with no multiplication of work.[2] The HyperPhysics site provides a calculation example showing force multiplication based on piston radii and areas.[2]
References
- "Pascal's Principle and Hydraulics", www.grc.nasa.gov. facts only, no text reused. grc.nasa.gov
- "Pressure", hyperphysics.phy-astr.gsu.edu. facts only, no text reused. hyperphysics.phy-astr.gsu.edu
- Wikipedia, "Pascal's law" (CC BY-SA 4.0), which cites: "Pascal's principle - Definition, Example, & Facts", britannica.com; "Pascal's Principle and Hydraulics", www.grc.nasa.gov; "Pressure", hyperphysics.phy-astr.gsu.edu; Bloomfield, "How Things Work: The Physics of Everyday Life", John Wiley & Sons, 2006, p. 153; Blaise Pascal, Traitez de l'Equilibre des Liqueurs (Treatise on the Equilibrium of Fluids), Paris, 1663.; (we also read that source) en.wikipedia.org
- Wikipedia, "Pascal's law" (CC BY-SA 4.0), which cites: perhaps first in an educational context; the attribution is found under this name in A. Merlette, L'encyclopédie des écoles, journal de l'enseignement primaire ; see e.g. E. Canon-Tapia in: Thor Thordarson (ed.) Studies in Volcanology, 2009, , p. 273. (original not read by us) en.wikipedia.org
- Wikipedia, "Pascal's law" (CC BY-SA 4.0), which cites: Merriman, "Treatise on hydraulics", J. Wiley, 1903, p. 22 (original not read by us) en.wikipedia.org
- Wikipedia, "Pascal's law" (CC BY-SA 4.0), which cites: Acheson, D. J. (1990), Elementary Fluid Dynamics, Oxford Applied Mathematics and Computing Science Series, Oxford University Press, (original not read by us) en.wikipedia.org
- Wikipedia, "Pascal's law" (CC BY-SA 4.0), which cites: Acott, Chris, "The diving "Law-ers": A brief resume of their lives", South Pacific Underwater Medicine Society Journal, 1999 (original not read by us) en.wikipedia.org
Each numbered sentence above was checked against the source it cites before publication. Sentences citing Wikipedia adapt text from the English Wikipedia article Pascal's law (contributors), used under CC BY-SA 4.0; this entry is available under the same licence. Other sources were used for facts only; no text or images are copied from them.
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Sources
Compiled from Wikipedia and the sources listed below. Text from Wikipedia is available under CC BY-SA 4.0; this entry is adapted from it.
- Wikipedia: Pascal's law (CC BY-SA 4.0).
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