Pascal (unit)

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Pascal (unit)

The pascal (symbol: Pa) is the SI derived unit

SI derived unit

SI derived units are part of the SI system of measurement Units of measurements and are derived from the seven SI base units.Note that while the names of all SI units are in lowercase, the symbols of units named after people are written with an initial capital letter ....
of pressure

Pressure

Pressure is the force per unit area applied to an object in a direction surface normal to the surface. Gauge pressure is the pressure relative to the local atmospheric or ambient pressure....
, stress

Stress (physics)

In continuum mechanics, stress is a measure of the average amount of force exerted per unit area. It is a measure of the intensity of the total internal forces acting within a body across imaginary internal surfaces, as a reaction to external applied forces and body forces....
, Young's modulus

Young's modulus

In solid mechanics, Young's modulus is a measure of the stiffness of an isotropic elastic material. It is also known as the Young modulus, modulus of elasticity, elastic modulus or tensile modulus....
and tensile strength

Tensile strength

Tensile strength , or is the Stress at which a material breaks or permanently deforms. Tensile strength is an Intensive and extensive properties and, consequently, does not depend on the size of the test specimen....
. It is a measure of force

Force

In physics, a force is that which can cause an object with mass to change its velocity. Force has both Euclidean_vector#Length of a vector and Direction , making it a Vector quantity....
per unit area

Area

Area is a quantity expressing the two-dimensional size of a defined part of a surface, typically a region bounded by a closed curve. The term surface area refers to the total area of the exposed surface of a 3-dimensional solid, such as the sum of the areas of the exposed sides of a polyhedron....
i.e. equivalent to one newton

Newton

The newton is the International System of Units SI derived unit of force, named after Isaac Newton in recognition of his work on classical mechanics....
per square meter or one joule

Joule

The joule is the SI derived unit of energy in the International System of Units. It is defined as:One joule is the amount of energy required to perform the following actions:...
per cubic meter. In everyday life, the pascal is perhaps best known from meteorological barometric pressure reports, where it occurs in the form of hectopascals (1 hPa = 100 Pa).. In other contexts, the kilopascal is more commonly used, for example on bicycle tire labels.

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Encyclopedia

The pascal (symbol: Pa) is the SI derived unit

SI derived unit

Pressure

Stress (physics)

Young's modulus

Tensile strength

Force

Area

Newton

The newton is the International System of Units SI derived unit of force, named after Isaac Newton in recognition of his work on classical mechanics....
per square meter or one joule

Joule

Atmospheric pressure

Atmospheric pressure is sometimes defined as the force per unit area exerted against a surface by the weight of air above that surface at any given point in the Earth's atmosphere....
(near sea level): one hectopascal is thus equivalent to a millibar

Bar (unit)

The bar , decibar and the millibar are units of pressure. They are not SI units, nor are they cgs units, but they are accepted for use with the SI....
; one atmosphere is equal to 1013.25 hPa.

Definition

1 pascal (Pa) = 1 N
Newton

The newton is the International System of Units SI derived unit of force, named after Isaac Newton in recognition of his work on classical mechanics....
/m
Metre

The metre or meter is a Unit of measurement of length. It is the SI base unit of length in the metric system and in the International System of Units , used around the world for general and scientific purposes....
² = 1 J
Joule

The joule is the SI derived unit of energy in the International System of Units. It is defined as:One joule is the amount of energy required to perform the following actions:...
/m
Metre

The metre or meter is a Unit of measurement of length. It is the SI base unit of length in the metric system and in the International System of Units , used around the world for general and scientific purposes....
³ = 1 kg
Kilogram

The kilogram or kilogrammeThe spelling kilogram is used by the International Committee for Weights and Measures and the U.S....
/(m
Metre

The metre or meter is a Unit of measurement of length. It is the SI base unit of length in the metric system and in the International System of Units , used around the world for general and scientific purposes....
·s
Second

The second , sometimes abbreviated sec., is the name of a units of measurement of time, and is the International System of Units SI base unit of time....
²)

Origin

The unit is named after Blaise Pascal

Blaise Pascal

Blaise Pascal , was a France mathematician, physicist, and religion philosopher. He was a child prodigy who was educated by his father, a civil servant....
, the eminent French

France

France , officially the French Republic , is a country whose Metropolitan France is located in Western Europe and that also comprises various Overseas departments and territories of France....
mathematician

Mathematician

A mathematician is a person whose primary area of study and/or research is the field of mathematics....
, physicist

Physicist

A physicist is a scientist who studies or practices physics. Physicists study a wide range of physical phenomena in many Physics#Major fields of physics spanning all length scales: from atom particles of which all ordinary matter is made to the behavior of the material Universe as a whole ....
, and philosopher noted for his experiments with a barometer

Barometer

A barometer is an instrument used to measure atmospheric pressure. It can measure the pressure exerted by the atmosphere by using water, air, or mercury ....
, an instrument to measure air pressure. The name pascal was adopted for the SI unit newton

Newton

The newton is the International System of Units SI derived unit of force, named after Isaac Newton in recognition of his work on classical mechanics....
per square metre

Square metre

The square metre is the SI derived unit of area, with symbol m?. It is defined as the area of a square whose sides measure exactly one metre....
by the 14th CGPM in 1971.

Miscellaneous

Standard atmospheric pressure is 101,325 Pa = 101.325 kPa = 1013.25 hPa = 1013.25 mbar = 760 Torr

Torr

The torr is a non-International System of Units unit of pressure defined as 1/760 of an Atmosphere . It was named after Evangelista Torricelli, an Italian physicist and mathematician who discovered the principle of the barometer in 1644....
. This definition is used for pneumatic fluid power (ISO R554), and in the aerospace (ISO 2533) and petroleum (ISO 5024) industries.

In 1985, IUPAC recommended that standard atmospheric pressure should be harmonized to 100,000 Pa = 1 bar

Bar (unit)

The bar , decibar and the millibar are units of pressure. They are not SI units, nor are they cgs units, but they are accepted for use with the SI....
= 750 Torr

Torr

The torr is a non-International System of Units unit of pressure defined as 1/760 of an Atmosphere . It was named after Evangelista Torricelli, an Italian physicist and mathematician who discovered the principle of the barometer in 1644....
. The same definition is used in the compressor and the pneumatic tool industries (ISO 2787).

The Unicode

Unicode

Unicode is a computing industry standard allowing computers to consistently represent and manipulate Character expressed in most of the world's writing systems....
computer character set has dedicated symbols for Pa and for kPa, but these exist merely for backward-compatibility with some older ideographic character-sets and are therefore deprecated.

Uses

The pascal (Pa) or kilopascal (kPa) as a unit of pressure measurement is widely used throughout the world and largely replaces the pounds per square inch (psi) unit except in some countries still using the Imperial measurement system.

Another unit for pressure measurement in common use today is millimetres of water (1 mmH₂O = 9.80665 Pa).

Meteorologists worldwide have for a long time measured atmospheric pressure in millibars. After the introduction of SI units, many preferred to preserve the customary pressure figures. Therefore, meteorologists use hectopascals (hPa) today for air pressure, which are equivalent to millibars, while similar pressures are given in kilopascals in practically all other fields, where the hecto prefix is hardly ever used. Since official metrication

Metrication

Metrication refers to the introduction of the Metric system as the international standard for physical measurements?a long-term series of independent and systematic conversions from the various separate localism systems of historical weights and measures....
, meteorologists in Canada use kilopascals (kPa), see for example and , although in some other countries hectopascals are still in use, see for example , , , , and .

1 hectopascal (hPa) = 100 Pa = 1 mbar.

1 kilopascal (kPa) = 1000 Pa = 10 hPa = 10 mbar.

In the cgs system, the unit of pressure is the barye

Barye

The barye , or sometimes barad, barrie, bary, baryd, baryed, or barie, was a Centimetre gram second system of units unit of pressure used in France....
(symbol ba), which is equal to one decipascal.

In the former mts system

Metre-tonne-second system of units

The metre-tonne-second or mts system of units is a system of physical units. It was invented in France, hence the unit names sth?ne and pi?ze, and was adopted only by the Soviet Union in 1933, and abolished there in 1955....
, the unit of pressure is the pièze

Pièze

The pieze is the unit of pressure in the metre-tonne-second system of units , used, e.g., in the former Soviet Union 1933-1955. It is defined as one sthene per square metre....
(symbol pz), which is equal to one kilopascal.

Vehicle owners' guides now specify tire

Tire

Tires, or tyres , are ring-shaped parts, either pneumatic or solid , that fit around wheels to protect them and enhance their function....
inflation in kilopascals.

Airtightness testing of buildings

Blower Door

A blower door is a diagnostic tool designed to measure the airtightness of buildings. and to help locate air leakage sites. A blower door consists of a calibrated blower for measuring an airflow rate, and a pressure-sensor device to measure the air pressure created by the fan flow....
is measured at 50 Pa or 0.2 inches of water.

Pascal (unit)

Definition

Origin

Miscellaneous

Uses

See also