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The SI unit of pressure is the pascal ( symbol: Pa ), defined as one newton per square metre.
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SI and pressure
In measurements of purely mechanical systems ( involving units of length, mass, force, energy, pressure, and so on ), the differences between CGS and SI are straightforward and rather trivial ; the unit-conversion factors are all powers of 10 arising from the relations and.
Thus, for example, the CGS unit of pressure, barye, is related to the CGS base units of length, mass, and time in the same way as the SI unit of pressure, pascal, is related to the SI base units of length, mass, and time:
* International Standard Atmosphere, a definition of pressure, temperature, humidity and so forth, under the SI convention
The SI unit for pressure is the pascal ( Pa ), equal to one newton per square metre ( N · m < sup >− 2 </ sup > or kg · m < sup >− 1 </ sup >· s < sup >− 2 </ sup >).
This special name for the unit was added in 1971 ; before that, pressure in SI was expressed in units such as N · m < sup >− 2 </ sup >.
* Pascal ( unit ) ( Pa ), the SI unit of pressure ( equivalent to one newton per square meter )
While pressure may be measured in any unit of force divided by any unit of area, the SI unit of pressure ( the newton per square metre ) is called the pascal ( Pa ) after the seventeenth-century philosopher and scientist Blaise Pascal.
The SI unit for pressure is the pascal ( Pa ), equal to one newton per square meter ( N / m < sup > 2 </ sup > or kg · m < sup >− 1 </ sup >· s < sup >− 2 </ sup >).
This special name for the unit was added in 1971 ; before that, pressure in SI was expressed simply as N / m < sup > 2 </ sup >.
where p is pressure in pascals, or N / m < sup > 2 </ sup > and Q is volumetric flow rate in m < sup > 3 </ sup >/ s in SI units.
Other units of pressure are defined in terms of SI units.
The International System of Units ( SI ) recognizes pressure as a derived unit with the dimension of force per area and designates the pascal ( Pa ) as its standard unit.
It is usually measured in dB above a reference pressure level of 0. 00002 Pa, i. e., 20 μPa ( micropascals ) in SI units.
The pascal ( symbol: Pa ) is the SI derived unit of pressure, internal pressure, stress, Young's modulus and tensile strength, named after the French mathematician, physicist, inventor, writer, and philosopher Blaise Pascal.
After the introduction of SI units, many preferred to preserve the customary pressure figures.
* Pascal, SI unit of pressure, 1 newton acting on an area of 1 square metre
The value of is typically expressed in ° C / bar ( SI units: K / Pa ) and depends on the type of gas and on the temperature and pressure of the gas before expansion.
* Pascal ( unit ), an SI derived unit of pressure
* p is pressure ( SI unit: pascal )
SI and is
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Only the product is required to calculate planetary positions for an ephemeris, which explains why ephemerides are calculated in astronomical units and not in SI units.
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Industry practice, more thoroughly documented at Timeline of binary prefixes and continuing today, is to specify hard drives using SI prefixes and symbols in their SI or " decimal " interpretation.
SI and pascal
The pascal can be expressed using SI derived units, or alternatively solely SI base units, as:
The name pascal was adopted for the SI unit newton per square metre by the 14th CGPM in 1971.
The pascal is also equivalent to the SI unit of energy density, J / m < sup > 3 </ sup >.
* Decipascal ( dPa ), an SI unit equivalent to one tenth of a pascal
The SI unit of modulus of elasticity ( E, or less commonly Y ) is the pascal ( Pa or N / m² or m < sup >− 1 </ sup >· kg · s < sup >− 2 </ sup >).
In the SI system, the unit is the pascal ( Pa ) ( or a multiple thereof, often megapascals ( MPa ), using the mega-prefix ); or, equivalently to pascals, newtons per square metre ( N / m² ).
In general, the SI unit of stress is the pascal, where 1 Pa = 1 N / m².
The bar is defined using the SI unit pascal, namely: ≡.
The SI unit for sound pressure p is the pascal ( symbol: Pa ).
In SI units, torque density is expressed in joules per cubic metre or equivalently newton-metres per cubic metre ( though dimensionally equivalent to the pascal, that is usually not used for this purpose ).
Shear modulus ' derived SI unit is the pascal ( Pa ), although it is usually expressed in gigapascals ( GPa ) or in thousands of pounds per square inch ( kpsi ).
In SI units, the unit is converted to the SI derived unit pascal ( Pa ), which is defined as one newton per square meter ( N / m < sup > 2 </ sup >).
0.139 seconds.