Pressure - Revision history

Jmdonev: 1 revision imported

2021-09-27T00:02:39Z

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energy>Ethan.boechler at 16:48, 13 September 2021

2021-09-13T16:48:19Z

← Older revision		Revision as of 16:48, 13 September 2021
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	[[category:371 topics]]		[[category:371 topics]]
	[[Category:Done ~~2018~~-06-01]]		[[Category:Done 2021-01-31]]
			[[Category: Translated to Spanish]]
			[[es:Presión]]
			[[Category:Translated to French]]
			[[fr:Pression]]
	<onlyinclude>'''Pressure''' is an important concept in physics, and is defined as the magnitude of [[force]] acting perpendicular to a surface, per unit area. The [[SI]] unit for pressure is the [[pascal]] (Pa), defined as 1 [[newton]] per [[meter]] squared.<ref name=press>R. Serway and J. Jewett, "Pressure," in ''Physics for Scientists and Engineers'', 8th ed., Belmont, CA: Cengage Learning, 2010, ch.14, sec.1, pp. 403</ref></onlyinclude>		<onlyinclude>'''Pressure''' is an important concept in physics, and is defined as the magnitude of [[force]] acting perpendicular to a surface, per unit area. The [[SI]] unit for pressure is the [[pascal]] (Pa), defined as 1 [[newton]] per [[meter]] squared.<ref name=press>R. Serway and J. Jewett, "Pressure," in ''Physics for Scientists and Engineers'', 8th ed., Belmont, CA: Cengage Learning, 2010, ch.14, sec.1, pp. 403</ref></onlyinclude>

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	==Fluid Pressure==		==Fluid Pressure==
	[[File:FluidContinuity.png\|400px\|thumb\|Figure 1: A decrease in cross sectional area increases force in these parts which increases the fluids velocity.<ref>A Plus Physics, ''Continuity for Fluids'' [Online], Available: http://www.aplusphysics.com/courses/honors/fluids/continuity.html</ref>]]		[[File:FluidContinuity.png\|400px\|thumb\|Figure 1: A decrease in cross sectional area increases force in these parts which increases the fluids velocity (v<sub>2</sub> is faster).<ref>A Plus Physics, ''Continuity for Fluids'' [Online], Available: http://www.aplusphysics.com/courses/honors/fluids/continuity.html</ref>]]
	In fluid mechanics, pressure can create many useful devices in different situations. In plumbing, different cross-sectional areas for the pipes creates higher speeds at different locations (see Figure 1). This controls how [[fluid]]s flow in rivers and hoses.		In fluid mechanics, pressure can create many useful devices in different situations. In plumbing, different cross-sectional areas for the pipes creates higher speeds at different locations, where smaller areas result in higher speeds (see Figure 1). This controls how [[fluid]]s flow in rivers and hoses.

	Pressure in fluids with no net motion, like the ocean or the [[atmosphere]], dictates much of what happens to the fluids. The atmosphere is a compressible fluid (changes [[volume]] when pushed) made up of many different [[gas]]es, so depending on where a person is on the Earth there will be a pressure acting on them (with pressure at sea level being defined as 1 [[standard atmosphere\|atm]]).		Pressure in fluids with no net motion, like the ocean or the [[atmosphere]], dictates much of what happens to the fluids. The atmosphere is a compressible fluid (changes [[volume]] when pushed) made up of many different [[gas]]es, so depending on where a person is on the Earth there will be a pressure acting on them (with pressure at sea level being defined as 1 [[standard atmosphere\|atm]]).

	For incompressible fluids like [[water]], the relationship <math>P=\rho gh</math> gives the pressure under a column of fluid (where '''<math>\rho</math>''' is the density of a fluid, <math>h</math> is the height, and <math>g</math> is the [[acceleration]] of [[gravity]]~~), instruments~~ like the [[mercury]] barometer (see Figure 2) can be used to determine pressures from the atmosphere.<ref>Hyperphysics, ''Mercury Barometer'' [Online], Available: http://hyperphysics.phy-astr.gsu.edu/hbase/pman.html#bar</ref>		For incompressible fluids like [[water]], the relationship <math>P=\rho gh</math> gives the pressure under a column of fluid, where '''<math>\rho</math>''' is the density of a fluid, <math>h</math> is the height, and <math>g</math> is the [[acceleration]] of [[gravity]]. Instruments like the [[mercury]] barometer (see Figure 2) can be used to determine pressures from the atmosphere.<ref>Hyperphysics, ''Mercury Barometer'' [Online], Available: http://hyperphysics.phy-astr.gsu.edu/hbase/pman.html#bar</ref>
	[[File:Pbar.gif\|thumbnail\|600px\|center\|Figure 2: Mercury barometer measuring atmospheric pressure.<ref>Hyperphysics, ''Mercury Barometer'' [Online], Available: http://hyperphysics.phy-astr.gsu.edu/hbase/pman.html#c4</ref>]]		[[File:Pbar.gif\|thumbnail\|600px\|center\|Figure 2: Mercury barometer measuring atmospheric pressure.<ref>Hyperphysics, ''Mercury Barometer'' [Online], Available: http://hyperphysics.phy-astr.gsu.edu/hbase/pman.html#c4</ref>]]

Jmdonev at 16:28, 2 August 2019

2019-08-02T16:28:07Z

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	<html>		<html>
	<iframe src="~~http~~://phet.colorado.edu/sims/html/under-pressure/latest/under-pressure_en.html" width="800" height="600" allowfullscreen></iframe>		<iframe src="https://phet.colorado.edu/sims/html/under-pressure/latest/under-pressure_en.html" width="800" height="600" allowfullscreen></iframe>
	</html>		</html>
	==For Further Reading==		==For Further Reading==

Jmdonev: 1 revision imported: Doing upload, largely of old redirects.

2018-06-04T16:52:23Z

1 revision imported: Doing upload, largely of old redirects.

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Jmdonev at 17:40, 1 June 2018

2018-06-01T17:40:00Z

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	~~[[Category:Done 2015-09-06]]~~
	[[category:371 topics]]		[[category:371 topics]]
	<onlyinclude>'''Pressure''' is an important concept in physics, and is defined as the magnitude of [[force]] acting perpendicular to a surface, per unit area. The [[SI]] unit for pressure is the [[pascal]], defined as 1 [[newton]] per [[meter]] squared.<ref name=press>R. Serway and J. Jewett, "Pressure," in ''Physics for Scientists and Engineers'', 8th ed., Belmont, CA: Cengage Learning, 2010, ch.14, sec.1, pp. 403</ref></onlyinclude>		[[Category:Done 2018-06-01]]
			<onlyinclude>'''Pressure''' is an important concept in physics, and is defined as the magnitude of [[force]] acting perpendicular to a surface, per unit area. The [[SI]] unit for pressure is the [[pascal]] (Pa), defined as 1 [[newton]] per [[meter]] squared.<ref name=press>R. Serway and J. Jewett, "Pressure," in ''Physics for Scientists and Engineers'', 8th ed., Belmont, CA: Cengage Learning, 2010, ch.14, sec.1, pp. 403</ref></onlyinclude>

	<m>P=\frac{F}{A}</m>,		<math>P=\frac{F}{A}</math>,
	where		where
	* P is pressure		* P is pressure
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	In fluid mechanics, pressure can create many useful devices in different situations. In plumbing, different cross-sectional areas for the pipes creates higher speeds at different locations (see Figure 1). This controls how [[fluid]]s flow in rivers and hoses.		In fluid mechanics, pressure can create many useful devices in different situations. In plumbing, different cross-sectional areas for the pipes creates higher speeds at different locations (see Figure 1). This controls how [[fluid]]s flow in rivers and hoses.

	Pressure in fluids with no net motion, like the ocean or the [[atmosphere]], dictates much of what happens to the fluids. The atmosphere is a compressible fluid (changes [[volume]] when pushed) made up of many different [[gas]]es, so depending on where a person is on the Earth there will be a pressure acting on them (with pressure at sea level being defined as 1 [[standard atmosphere\|atm]]). For incompressible fluids, like [[water]], the relationship <m>P=\rho gh</m> gives the ~~[[density]]~~ under a column of fluid (where '''<m>\rho</m>''' is the density of a fluid, <m>h</m> is the height, and <m>g</m> is the [[acceleration]] of [[gravity]]), instruments like the [[mercury]] barometer (see Figure 2) can be used to determine pressures from the atmosphere.<ref>Hyperphysics, ''Mercury Barometer'' [Online], Available: http://hyperphysics.phy-astr.gsu.edu/hbase/pman.html#bar</ref>		Pressure in fluids with no net motion, like the ocean or the [[atmosphere]], dictates much of what happens to the fluids. The atmosphere is a compressible fluid (changes [[volume]] when pushed) made up of many different [[gas]]es, so depending on where a person is on the Earth there will be a pressure acting on them (with pressure at sea level being defined as 1 [[standard atmosphere\|atm]]).

			For incompressible fluids like [[water]], the relationship <math>P=\rho gh</math> gives the pressure under a column of fluid (where '''<math>\rho</math>''' is the density of a fluid, <math>h</math> is the height, and <math>g</math> is the [[acceleration]] of [[gravity]]), instruments like the [[mercury]] barometer (see Figure 2) can be used to determine pressures from the atmosphere.<ref>Hyperphysics, ''Mercury Barometer'' [Online], Available: http://hyperphysics.phy-astr.gsu.edu/hbase/pman.html#bar</ref>
	[[File:Pbar.gif\|thumbnail\|600px\|center\|Figure 2: Mercury barometer measuring atmospheric pressure.<ref>Hyperphysics, ''Mercury Barometer'' [Online], Available: http://hyperphysics.phy-astr.gsu.edu/hbase/pman.html#c4</ref>]]		[[File:Pbar.gif\|thumbnail\|600px\|center\|Figure 2: Mercury barometer measuring atmospheric pressure.<ref>Hyperphysics, ''Mercury Barometer'' [Online], Available: http://hyperphysics.phy-astr.gsu.edu/hbase/pman.html#c4</ref>]]

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	<iframe src="http://phet.colorado.edu/sims/html/under-pressure/latest/under-pressure_en.html" width="800" height="600" allowfullscreen></iframe>		<iframe src="http://phet.colorado.edu/sims/html/under-pressure/latest/under-pressure_en.html" width="800" height="600" allowfullscreen></iframe>
	</html>		</html>
			==For Further Reading==

			*[[Absolute pressure]]
			*[[Gauge pressure]]
			*[[Tire pressure]]
			*[[Force]]
			*[[Fluid]]
			*[[Special:Random\|A random page]]

	==References==		==References==
	{{reflist}}		{{reflist}}
	[[Category:Uploaded]]		[[Category:Uploaded]]

J.williams: 1 revision imported

2015-09-18T16:50:56Z

1 revision imported

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Jhanania at 19:53, 3 September 2015

2015-09-03T19:53:30Z

← Older revision		Revision as of 19:53, 3 September 2015
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	[[Category:Done 2015-07-24]]		[[Category:Done 2015-09-06]]
	[[category:371 topics]]		[[category:371 topics]]
	<onlyinclude>'''Pressure''' is an important concept in physics, and is defined as the magnitude of [[force]] acting perpendicular to a surface, per unit area. The [[SI]] unit for pressure is the [[pascal]], defined as 1 [[newton]] per [[meter]] squared.<ref name=press>R. Serway and J. Jewett, "Pressure," in ''Physics for Scientists and Engineers'', 8th ed., Belmont, CA: Cengage Learning, 2010, ch.14, sec.1, pp. 403</ref></onlyinclude>		<onlyinclude>'''Pressure''' is an important concept in physics, and is defined as the magnitude of [[force]] acting perpendicular to a surface, per unit area. The [[SI]] unit for pressure is the [[pascal]], defined as 1 [[newton]] per [[meter]] squared.<ref name=press>R. Serway and J. Jewett, "Pressure," in ''Physics for Scientists and Engineers'', 8th ed., Belmont, CA: Cengage Learning, 2010, ch.14, sec.1, pp. 403</ref></onlyinclude>
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	==Fluid Pressure==		==Fluid Pressure==
	[[File:FluidContinuity.png\|400px\|thumb\|Figure 1: A decrease in cross sectional area increases force in these parts which increases the fluids velocity.<ref>A Plus Physics, ''Continuity for Fluids'' [Online], Available: http://www.aplusphysics.com/courses/honors/fluids/continuity.html</ref>]]		[[File:FluidContinuity.png\|400px\|thumb\|Figure 1: A decrease in cross sectional area increases force in these parts which increases the fluids velocity.<ref>A Plus Physics, ''Continuity for Fluids'' [Online], Available: http://www.aplusphysics.com/courses/honors/fluids/continuity.html</ref>]]
	In fluid mechanics, pressure can create many useful devices in different situations. In plumbing, different cross-sectional areas for the pipes creates higher speeds at different locations (see Figure 1). This controls how ~~fluids~~ flow in rivers and hoses.		In fluid mechanics, pressure can create many useful devices in different situations. In plumbing, different cross-sectional areas for the pipes creates higher speeds at different locations (see Figure 1). This controls how [[fluid]]s flow in rivers and hoses.

	Pressure in fluids with no net motion, like the ocean or the atmosphere, dictates much of what happens to the fluids. The atmosphere is a compressible fluid (changes volume when pushed) made up of many different [[gas]]es, so depending on where a person is on the Earth there will be a pressure acting on them (with pressure at sea level being defined as 1 [[standard atmosphere\|atm]]). For incompressible fluids, like water, the relationship <m>P=\rho gh</m> gives the density under a column of fluid (where '''<m>\rho</m>''' is the density of a fluid, <m>h</m> is the height, and <m>g</m> is the acceleration of gravity), instruments like the mercury barometer (see Figure 2) can be used to determine pressures from the atmosphere.<ref>Hyperphysics, ''Mercury Barometer'' [Online], Available: http://hyperphysics.phy-astr.gsu.edu/hbase/pman.html#bar</ref>		Pressure in fluids with no net motion, like the ocean or the [[atmosphere]], dictates much of what happens to the fluids. The atmosphere is a compressible fluid (changes [[volume]] when pushed) made up of many different [[gas]]es, so depending on where a person is on the Earth there will be a pressure acting on them (with pressure at sea level being defined as 1 [[standard atmosphere\|atm]]). For incompressible fluids, like [[water]], the relationship <m>P=\rho gh</m> gives the [[density]] under a column of fluid (where '''<m>\rho</m>''' is the density of a fluid, <m>h</m> is the height, and <m>g</m> is the [[acceleration]] of [[gravity]]), instruments like the [[mercury]] barometer (see Figure 2) can be used to determine pressures from the atmosphere.<ref>Hyperphysics, ''Mercury Barometer'' [Online], Available: http://hyperphysics.phy-astr.gsu.edu/hbase/pman.html#bar</ref>
	[[File:Pbar.gif\|thumbnail\|600px\|center\|Figure 2: Mercury barometer measuring atmospheric pressure.<ref>Hyperphysics, ''Mercury Barometer'' [Online], Available: http://hyperphysics.phy-astr.gsu.edu/hbase/pman.html#c4</ref>]]		[[File:Pbar.gif\|thumbnail\|600px\|center\|Figure 2: Mercury barometer measuring atmospheric pressure.<ref>Hyperphysics, ''Mercury Barometer'' [Online], Available: http://hyperphysics.phy-astr.gsu.edu/hbase/pman.html#c4</ref>]]

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	===Gas Pressure===		===Gas Pressure===
	[[File:WindFormation.gif\|right\|400px\|thumbnail\|Figure 3: The formation of wind due to pressure differences.<ref>M. Pidwirny. (2013, Nov. 4). “Forces Acting to Create Wind” in ''Fundamentals of Physical Geography, 2nd Ed.'' [Online]. Available: http://www.physicalgeography.net/fundamentals/7n.html</ref>]]		[[File:WindFormation.gif\|right\|400px\|thumbnail\|Figure 3: The formation of wind due to pressure differences.<ref>M. Pidwirny. (2013, Nov. 4). “Forces Acting to Create Wind” in ''Fundamentals of Physical Geography, 2nd Ed.'' [Online]. Available: http://www.physicalgeography.net/fundamentals/7n.html</ref>]]
	Pressure is determined by the flow of mass from a region of high pressure to a region of low pressure, and this is most visible with gasses.		Pressure is determined by the flow of [[mass]] from a region of high pressure to a region of low pressure, and this is most visible with gasses.

	For example, a balloon being filled with air expands because the pressure inside the balloon is increasing to pressures higher than those outside of it. Since pressure is a property that determines which direction mass flows, as soon as the balloon is released the air moves from a region of high pressure to a region of low pressure and the balloon deflates.<ref>UC Davis Chem Wiki, ''Gas Pressure'' [Online], Available: http://chemwiki.ucdavis.edu/Physical_Chemistry/Physical_Properties_of_Matter/Phases_of_Matter/Gases/Gas_Pressure</ref>		For example, a balloon being filled with [[air]] expands because the pressure inside the balloon is increasing to pressures higher than those outside of it. Since pressure is a property that determines which direction mass flows, as soon as the balloon is released the air moves from a region of high pressure to a region of low pressure and the balloon deflates.<ref>UC Davis Chem Wiki, ''Gas Pressure'' [Online], Available: http://chemwiki.ucdavis.edu/Physical_Chemistry/Physical_Properties_of_Matter/Phases_of_Matter/Gases/Gas_Pressure</ref>

	This tendency of pressure to flow from high pressure regions to low pressure regions is the driving force of [[wind]] on the Earth. Due to uneven heating of the Earth, different areas are at higher pressures than others so this causes the flow of air in the atmosphere (shown in Figure 3). Most [[weather]] phenomena, from hurricanes to tornadoes, are a product of pressure and [[temperature]], and are also influenced by the rotation of the Earth (see [[Wind#Coriolis effect\|Coriolis effect]]).		This tendency of pressure to flow from high pressure regions to low pressure regions is the driving force of [[wind]] on the Earth. Due to uneven heating of the Earth, different areas are at higher pressures than others so this causes the flow of air in the atmosphere (shown in Figure 3). Most [[weather]] phenomena, from hurricanes to tornadoes, are a product of pressure and [[temperature]], and are also influenced by the rotation of the Earth (see [[Wind#Coriolis effect\|Coriolis effect]]).

J.williams: 1 revision imported

2015-08-26T21:31:32Z

1 revision imported

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J.williams at 16:58, 12 August 2015

2015-08-12T16:58:39Z

New page

[[Category:Done 2015-07-24]]
[[category:371 topics]]
<onlyinclude>'''Pressure''' is an important concept in physics, and is defined as the magnitude of [[force]] acting perpendicular to a surface, per unit area. The [[SI]] unit for pressure is the [[pascal]], defined as 1 [[newton]] per [[meter]] squared.<ref name=press>R. Serway and J. Jewett, "Pressure," in ''Physics for Scientists and Engineers'', 8th ed., Belmont, CA: Cengage Learning, 2010, ch.14, sec.1, pp. 403</ref></onlyinclude>

<m>P=\frac{F}{A}</m>,
where
* P is pressure
* F is the force applied perpendicular (normal) to the surface, and
* A is the area of the applied force.

An easy way to understand pressure is to imagine holding a tack, and pressing it ''lightly'' between forefinger and thumb, with the sharp end on the thumb and the head on the forefinger. The thumb will begin to feel pain immediately while the forefinger will not. The tack is exerting the same amount of force on both thumb and forefinger, but the pressure on the thumb is much larger because of the small area over which the force is applied.<ref name=press/>

Pressure is important in many physical applications; it is a key concept of [[fluid mechanics]], used in the [[ideal gas law]] to describe the energy of a gas, and many more situations.

==Fluid Pressure==
[[File:FluidContinuity.png|400px|thumb|Figure 1: A decrease in cross sectional area increases force in these parts which increases the fluids velocity.<ref>A Plus Physics, ''Continuity for Fluids'' [Online], Available: http://www.aplusphysics.com/courses/honors/fluids/continuity.html</ref>]]
In fluid mechanics, pressure can create many useful devices in different situations. In plumbing, different cross-sectional areas for the pipes creates higher speeds at different locations (see Figure 1). This controls how fluids flow in rivers and hoses.

Pressure in fluids with no net motion, like the ocean or the atmosphere, dictates much of what happens to the fluids. The atmosphere is a compressible fluid (changes volume when pushed) made up of many different [[gas]]es, so depending on where a person is on the Earth there will be a pressure acting on them (with pressure at sea level being defined as 1 [[standard atmosphere|atm]]). For incompressible fluids, like water, the relationship <m>P=\rho gh</m> gives the density under a column of fluid (where '''<m>\rho</m>''' is the density of a fluid, <m>h</m> is the height, and <m>g</m> is the acceleration of gravity), instruments like the mercury barometer (see Figure 2) can be used to determine pressures from the atmosphere.<ref>Hyperphysics, ''Mercury Barometer'' [Online], Available: http://hyperphysics.phy-astr.gsu.edu/hbase/pman.html#bar</ref>
[[File:Pbar.gif|thumbnail|600px|center|Figure 2: Mercury barometer measuring atmospheric pressure.<ref>Hyperphysics, ''Mercury Barometer'' [Online], Available: http://hyperphysics.phy-astr.gsu.edu/hbase/pman.html#c4</ref>]]

See [http://hyperphysics.phy-astr.gsu.edu/hbase/pflu.html hyperphysics] for more information about static fluid pressure.

===Gas Pressure===
[[File:WindFormation.gif|right|400px|thumbnail|Figure 3: The formation of wind due to pressure differences.<ref>M. Pidwirny. (2013, Nov. 4). “Forces Acting to Create Wind” in ''Fundamentals of Physical Geography, 2nd Ed.'' [Online]. Available: http://www.physicalgeography.net/fundamentals/7n.html</ref>]]
Pressure is determined by the flow of mass from a region of high pressure to a region of low pressure, and this is most visible with gasses.

For example, a balloon being filled with air expands because the pressure inside the balloon is increasing to pressures higher than those outside of it. Since pressure is a property that determines which direction mass flows, as soon as the balloon is released the air moves from a region of high pressure to a region of low pressure and the balloon deflates.<ref>UC Davis Chem Wiki, ''Gas Pressure'' [Online], Available: http://chemwiki.ucdavis.edu/Physical_Chemistry/Physical_Properties_of_Matter/Phases_of_Matter/Gases/Gas_Pressure</ref>

This tendency of pressure to flow from high pressure regions to low pressure regions is the driving force of [[wind]] on the Earth. Due to uneven heating of the Earth, different areas are at higher pressures than others so this causes the flow of air in the atmosphere (shown in Figure 3). Most [[weather]] phenomena, from hurricanes to tornadoes, are a product of pressure and [[temperature]], and are also influenced by the rotation of the Earth (see [[Wind#Coriolis effect|Coriolis effect]]).

See also [[absolute pressure]], [[gauge pressure]] and [[tire pressure]] for more information on how pressure relates to [[energy]]. Visit [http://hyperphysics.phy-astr.gsu.edu/hbase/press.html#pre hyperphysics] for more information about pressure.

==PhET Simulation==

The PhET simulation provided by the University of Colorado explores how pressure changes with fluid density, depth, gravity, and atmospheric conditions. Drag and drop the pressure gauge to measure pressure at various depths and locations.

<html>
<iframe src="http://phet.colorado.edu/sims/html/under-pressure/latest/under-pressure_en.html" width="800" height="600" allowfullscreen></iframe>
</html>

==References==
{{reflist}}
[[Category:Uploaded]]