- List of physical quantities
This is a list of physical quantities.
The first table lists the base quantities used in the
International System of Units to define the physical dimension of physical quantities fordimensional analysis . Note that the angle and solid angle are included in this list but are actually dimensionless quantities. The second table list the other physical quantities.Note that neither the names nor the symbols used for the physical quantities are international standards. Some quantities are known under several different names such as the magnetic "B-field" which known as the "magnetic flux density", the "magnetic induction" or simply as the "magnetic field" depending on the context. Similarly, surface tension can be denoted by either "σ", "γ" or "T". The table usually list only one name and symbol.
The final column lists some special properties some of the quantities have such as their scaling behavior (i.e. whether the quantity is intensive or extensive), their transformation properties (i.e. whether the quantity is a
scalar ,vector ortensor ) or whether the quantity is conserved. {|class="wikitable sortable" align="center" border="1" cellspacing="0" cellpadding="3" style="width:100%;min-width:95ex;text-align:left"
-! style="width:18ex" | Derived quantity! style="width: 5ex" | Symbol! style="min-width:30ex" class="unsortable"| Description! style="width:20ex" class="unsortable"| SI units! style="width:15ex" class="unsortable"| Dimension! style="width:25ex" class="unsortable"| Comments
-Absorbed dose rate |Absorbed dose received per unit of time.
Gy s−1
style="text-align: center" | L2 T−3|
-Acceleration
style="text-align: center" | "a"
Rate of change of the speed or velocity of an object.
m s−2
style="text-align: center" | L T−2
scalar or vector
-Angular acceleration
style="text-align: center" | "α"
Rate of change in angular speed or velocity.
rad s−2
style="text-align: center" | T−2|
-Angular speed (orangular velocity )
style="text-align: center" | "ω" or "ω"
The angle incremented in a plane by a segment connecting an object and a reference point.
rad s−1
style="text-align: center" | T−1
scalar or pseudovector
-Angular momentum
style="text-align: center" | "L"
Measure of the extent and direction and object rotates about a reference point.
kg m2 s−1
style="text-align: center" | M L2 T−1
conserved quantity, pseudovector
-Area
style="text-align: center" | "A"
The two dimensional extent of an object.
m2
style="text-align: center" | L2|
-Area density
style="text-align: center" | "ρA"
The amount of mass per unit area of a two dimensional object.
kg m−2
style="text-align: center" | M L−2|
-Capacitance
style="text-align: center" | "C"
Measure for the amount of stored charge for a given potential.farad (F = A2 s4 kg−1 m−2)
style="text-align: center" | I2 T4 M−1 L−2|
-Catalytic activity |
Change inreaction rate due to presence of acatalyst .katal (kat = mol s−1)
style="text-align: center" | N T−1|
-Catalytic activity concentration |
Change inreaction rate due to presence of acatalyst per unit volume of the system.
kat m−3
style="text-align: center" | N L−3 T−1|
-Chemical potential
style="text-align: center" | "μ"
The amount of energy needed to add a particle to a system.
J mol−1
style="text-align: center" | M L2 T−2 N−1
intensive
-Molar concentration
style="text-align: center" | "C"
Amount of substance per unit volume.
mol m−3
style="text-align: center" | N L−3
intensive
-Current density
style="text-align: center" | "J"
Amount of electric current flowing through a surface.
A m−2
style="text-align: center" | I L−2|
-Dose equivalent
style="text-align: center" | "H"
Measure for the received amount of radiation adjusted for the effect of different types of radiant on biological tissue.sievert (Sv = m2 s−2)
style="text-align: center" | L2 T−2|
-Dynamic Viscosity
style="text-align: center" | "η"
Measure for the resistance of an incompressible fluid to stress.
Pa s
style="text-align: center" | M L−1 T−1|
-Electric Charge
style="text-align: center" | "Q"
Amount of electric charge.coulomb (C = A s)
style="text-align: center" | I T
extensive, conserved quantity
-Electric charge density
style="text-align: center" | "ρQ"
Amount of electric charge per unit volume.
C m−3
style="text-align: center" | I T L−3
intensive
-Electric displacement
style="text-align: center" | "D"
Strength of the electric displacement.
C m−2
style="text-align: center" | I T L−2
vector field
-Electric field strength
style="text-align: center" | "E"
Strength of the electric field.
V m−1
style="text-align: center" | M I−1 L2 T−3
vector field
-Electrical conductance
style="text-align: center" | "G"
Meausure for how easily current flows through a material.
siemens (S = A2 s3 kg−1 m−2)
style="text-align: center" | L−2 M−1 T3 I2
scalar
-Electric potential
style="text-align: center" | "V"
The amount of work required to bring a unit charge into an electric field from infinity.volt (V = kg m2 A−1 s−3)
style="text-align: center" | L2 M T–3 I–1
scalar
-Electrical resistance
style="text-align: center" | "R"
The degree to which an object opposes the passage of an electric current.
ohm (Ω = kg m2 A−2 s−3)
style="text-align: center" | L2 M T–3 I–2
scalar
-Energy
style="text-align: center" | "E"
The capacity of a body or system to do work.joule (J = kg m2 s−2)
style="text-align: center" | M L2 T−2
extensive, scalar, conserved quantity
-Energy density
style="text-align: center" | "ρE"
Amount of energy per unit volume.
J m−3
style="text-align: center" | M L−1 T−2
intensive
-Entropy
style="text-align: center" | "S"
Measure for the amount of available states for a system.
J K−1
style="text-align: center" | M L2 T−2 Θ−1
extensive, scalar
-Force
style="text-align: center" | "F"
The external cause of acceleration, acting on an object.newton (N = kg m s−2)
style="text-align: center" | M L T−2
vector
-Frequency
style="text-align: center" | "f"
The number of times something happens in a period of time.hertz (Hz =s−1)
style="text-align: center" | T−1|
-Half-life
style="text-align: center" | "t1/2"
The time needed for a quantity to decay to half its original value.
s
style="text-align: center" | T |
-Heat
style="text-align: center" | "Q"
Amount of energy transferred between systems due to temperature difference.
J
style="text-align: center" | M L2 T−2 |
-Heat capacity
style="text-align: center" | "Cp"
Amount of energy needed to raise the temperature of a system by one degree.
J K−1
style="text-align: center" | M L2 T−2 Θ−1
extensive
-
Heat flux density
style="text-align: center" | "Unicode|ϕQ"
Amount of heat flowing through a surface per unit area.
W m−2
style="text-align: center" | M T−2 |
-Illuminance
style="text-align: center" | "Ev"
Total luminous flux incident to a surface per unit area.lux (lx = cd sr m−2)
style="text-align: center" | J L−2|
-
Impedance
style="text-align: center" | "Z"
Measure for the resistance of an electrical circuit against an alternating current.
ohm (Ω = kg m2 A−2 s−3)
style="text-align: center" | L2 M T–3 I–2
complex scalar
-Index of refraction
style="text-align: center" | "n"
The factor by which thespeed of light is reduce in a medium.|
style="text-align: center" | 1
intensive
-Inductance
style="text-align: center" | "L"
Measure for the amount of magnetic flux generated for a certain current run through a circuit.
henry (H = kg m2 A−2 s−2)
style="text-align: center" | M L2 T−2 I−2|
-Irradiance
style="text-align: center" | "E"
Power of electromagnetic radiation flowing through a surface per unit area.
W m−2
style="text-align: center" | M T−2 |
-Linear density
style="text-align: center" | "ρl"
Amount of mass per unit length of a one dimensional object.|
style="text-align: center" | M L−1|
-Luminous flux (or "luminous power")
style="text-align: center" | "F"
Perceived power of a light source.
lumen (lm = cd sr)
style="text-align: center" | J|
-Magnetic field strength
style="text-align: center" | "H"
Strength of a magnetic field in a material.
A m−1
style="text-align: center" | I L−1
vector field
-Magnetic flux
style="text-align: center" | "Φ"
Measure of quantity ofmagnetism , taking account of the strength and the extent of amagnetic field .
weber (Wb = kg m2 A−1 s−2)
style="text-align: center" | M L2 T−2 I−1
scalar
-Magnetic flux density
style="text-align: center" | "B"
Measure for the strength of the magnetic field.
tesla (T = kg A−1 s−2)
style="text-align: center" | M T−2 I−1
pseudovector field
-Magnetization
style="text-align: center" | "M"
Amount of magnetic moment per unit volume.
A m−1
style="text-align: center" | I L−1
vector field
-Mass fraction
style="text-align: center" | "x"
Mass of a substance as a fraction of the total mass.
kg/kg
style="text-align: center" | 1
intensive
-
(Mass) Density (volume density)
style="text-align: center" | "ρ"
The amount of mass per unit volume of a three dimensional object.
kg m−3
style="text-align: center" | M L−3
intensive
-Mean lifetime
style="text-align: center" | "τ"
Average time needed for a particle to decay.
s
style="text-align: center" | T
intensive
-Molar energy |
Amount of energy present is a system per unit amount of substance.
J mol−1
style="text-align: center" | M L2 T−2 N−1
intensive
-Molar entropy |
Amount of entropy present in a system per unit amount of substance.
J K−1 mol−1
style="text-align: center" | M L2 T−2 Θ−1 N−1
intensive
-Molar heat capacity
style="text-align: center" | "c"
Heat capacity of a material per unit amount of substance.
J K−1 mol−1
style="text-align: center" | M L2 T−2 N−1
intensive
-Moment of inertia
style="text-align: center" | "I"
Inertia of an object with respect to angular acceleration.
kg m2
style="text-align: center" | M L2
scalar
-Momentum
style="text-align: center" | "p"
Product of an object's mass and velocity.
N s
style="text-align: center" | M L T−1
vector, extensive
-Permeability
style="text-align: center" | "μ"
Measure for how the magnetization of material is affected by the application of an external magnetic field.
H m−1
style="text-align: center" | M L L−2 I−2
intensive
-Permittivity
style="text-align: center" | "ε"
Measure for how the polarization of a material is affected by the application of an external electric field.
F m−1
style="text-align: center" | I2 M−1 L−2 T4
intensive
-
Power
style="text-align: center" | "P"
The rate of change in energy over time.watt (W)
style="text-align: center" | M L2 T−3
extensive
-Pressure
style="text-align: center" | "p"
Amount of force per unit area.
pascal (Pa = kg m−1 s−2)
style="text-align: center" | M L−1 T−2
intensive
-
(Radioactive) Activity
style="text-align: center" | "A"
Number of particles decaying per unit time.becquerel (Bq = s−1)
style="text-align: center" | T−1
extensive
-
(Radioactive) Dose
style="text-align: center" | "D"
Amount of energy absorbed by biological tissue from ionizing radiation per unit mass.gray (unit) (Gy = m2 s−2)
style="text-align: center" | L2 T−2|
-Radiance
style="text-align: center" | "L"
Power of emitted electromagnetic radiation per solid angle and per projected source area.
W m−2 sr−1
style="text-align: center" | M L2 T−3|
-Radiant intensity
style="text-align: center" | "I"
Power of emitted electromagnetic radiation per solid angle.
W sr−1
style="text-align: center" | M L2 T−3
scalar
-Reaction rate
style="text-align: center" | "r"
Measure for speed of a chemical reaction.
mol m−3 s−1
style="text-align: center" | N L−3 T−1
intensive
-Speed
style="text-align: center" | "v"
Rate of change of the position of an object.
m s−1
style="text-align: center" | L T−1
scalar
-Specific energy |
Amount of energy present per unit mass.
J kg−1
style="text-align: center" | L2 T−2
intensive
-Specific heat capacity
style="text-align: center" | "c"
Heat capacity per unit mass.
J kg−1 K−1
style="text-align: center" | L2 T−2 Θ−1
intensive
-Specific volume
style="text-align: center" | "v"
The volume occupied by a unit mass of material (reciprocal of density).
m3 kg−1
style="text-align: center" | L3 M−1
intensive
-
Spin
style="text-align: center" | "S"
Intrinsic property of particles, roughly to be interpreted as the intrinsicangular momentum of the particle.
kg m2 s−1
style="text-align: center" | M L2 T−1|
-
Stress
style="text-align: center" | "σ"
Amount of force exerted per surface area.
Pa
style="text-align: center" | M L−1 T−2
2-tensor. (or scalar)
-Surface tension
style="text-align: center" | "γ"
Amount of work needed to change the surface of a liquid by a unit surface area.
N m−1 or J m−2
style="text-align: center" | M T−2|
-Thermal conductivity
style="text-align: center" | "k"
Measure for the easy with which a material conducts electricity.
W m−1 K−1
style="text-align: center" | M L−1 T−3 Θ−1
intensive
-Torque (moment of force)
style="text-align: center" | "T"
Product of a force and the perpendicular distance of the force from the point about which it is exerted.
N m
style="text-align: center" | M L2 T−2
pseudovector
-Velocity
style="text-align: center" | "v"
Speed of an object in a chosen direction.
m s−1
style="text-align: center" | L T−1
vector
-Volume
style="text-align: center" | "V"
The three dimensional extent of an object.
m3
style="text-align: center" | L3
extensive
-Wavelength
style="text-align: center" | "λ"
Distance between repeating units of a propagating wave.
m
style="text-align: center" | L|
-Wavenumber
style="text-align: center" | "k"
Reciprocal of the wavelength.
m−1
style="text-align: center" | L−1|
-Weight
style="text-align: center" | "w"
Amount of gravitation force exerted on an object.newton (N = kg m s−2)
style="text-align: center" | M L T−2|
-
Work
style="text-align: center" | "W"
Energy dissipated by a force moving over a distance, scalar product of the force and the movement vector.joule (J = kg m2 s−2)
style="text-align: center" | M L2 T−2
scalar
-
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