Derived quantity
|
Symbol
|
Description
|
SI derived unit
|
Dimension
|
Comments
|
Absorbed dose rate
|
D
|
Absorbed dose received per unit of time
|
Gy/s
|
L2 T−3
|
|
Action
|
S
|
Momentum of particle multiplied by distance travelled
|
J/Hz
|
L2 M T−1
|
scalar
|
Angular acceleration
|
ωa
|
Change in angular velocity per unit time
|
rad/s2
|
T−2
|
|
Area
|
A
|
Extent of a surface
|
m2
|
L2
|
extensive, bivector or scalar
|
Area density
|
ρA
|
Mass per unit area
|
kg⋅m−2
|
L−2 M
|
intensive
|
Capacitance
|
C
|
Stored charge per unit electric potential
|
farad (F = C/V)
|
L−2 M−1 T4 I2
|
scalar
|
Catalytic activity concentration
|
|
Change in reaction rate due to presence of a catalyst per unit volume of the system
|
kat⋅m−3
|
L−3 T−1 N
|
intensive
|
Chemical potential
|
μ
|
Energy per unit change in amount of substance
|
J/mol
|
L2 M T−2 N−1
|
intensive
|
Dose equivalent
|
H
|
Received radiation adjusted for the effect on biological tissue
|
sievert (Sv = J/kg)
|
L2 T−2
|
intensive
|
Dynamic viscosity
|
v
|
Measure for the resistance of an incompressible fluid to stress
|
Pa⋅s
|
L−1 M T−1
|
intensive
|
Electric charge
|
Q
|
The force per unit electric field strength
|
coulomb (C = A⋅s)
|
T I
|
extensive, conserved
|
Electric charge density
|
ρQ
|
Electric charge per unit volume
|
C/m3
|
L−3 T I
|
intensive
|
Electrical conductance
|
G
|
Measure for how easily current flows through a material
|
siemens (S = Ω−1)
|
L−2 M−1 T3 I2
|
scalar
|
Electrical conductivity
|
σ
|
Measure of a material's ability to conduct an electric current
|
S/m
|
L−3 M−1 T3 I2
|
scalar
|
Electric potential
|
φ
|
Energy required to move a unit charge through an electric field from a reference point
|
volt (V = J/C)
|
L2 M T−3 I−1
|
extensive, scalar
|
Electrical resistance
|
R
|
Electric potential per unit electric current
|
ohm (Ω = V/A)
|
L2 M T−3 I−2
|
extensive, scalar, assumes linearity
|
Electrical resistivity
|
ρe
|
Bulk property equivalent of electrical resistance
|
ohm-metre (Ω⋅m)
|
L3 M T−3 I−2
|
extensive, scalar, conserved
|
Energy
|
E
|
Energy
|
joule (J)
|
L2 M T−2
|
|
Energy density
|
?
|
Energy per volume
|
J⋅m−3
|
L−1 M T−2
|
intensive
|
Entropy
|
S
|
Logarithmic measure of the number of available states of a system
|
J/K
|
L2 M T−2 Θ−1
|
extensive, scalar
|
Force
|
F→
|
Transfer of momentum per unit time
|
newton (N = kg⋅m⋅s−2)
|
L M T−2
|
extensive, vector
|
Frequency
|
f
|
Number of (periodic) occurrences per unit time
|
hertz (Hz = s−1)
|
T−1
|
scalar
|
Half-life
|
t1/2
|
Time for a quantity to decay to half its initial value
|
s
|
T
|
|
Heat
|
Q
|
Thermal energy
|
joule (J)
|
L2 M T−2
|
|
Heat capacity
|
Cp
|
Energy per unit temperature change
|
J/K
|
L2 M T−2 Θ−1
|
extensive
|
Heat flux density
|
ϕQ
|
Heat flow per unit time per unit surface area
|
W/m2
|
M T−3
|
|
Illuminance
|
Ev
|
Wavelength-weighted luminous flux per unit surface area
|
lux (lx = cd⋅sr/m2)
|
L−2 J
|
|
Impedance
|
Z
|
Resistance to an alternating current of a given frequency, including effect on phase
|
ohm (Ω)
|
L2 M T−3 I−2
|
complex scalar
|
Inductance
|
L
|
Magnetic flux generated per unit current through a circuit
|
henry (H)
|
L2 M T−2 I−2
|
scalar
|
Irradiance
|
E
|
Electromagnetic radiation power per unit surface area
|
W/m2
|
M T−3
|
intensive
|
Intensity
|
I
|
Power per unit cross sectional area
|
W/m2
|
M T−3
|
intensive
|
Linear density
|
ρl
|
Mass per unit length
|
kg⋅m−1
|
L−1 M
|
|
Luminous flux (or luminous power)
|
F
|
Perceived power of a light source
|
lumen (lm = cd⋅sr)
|
J
|
|
Mach number (or mach)
|
M
|
Ratio of flow velocity to the local speed of sound
|
unitless
|
1
|
|
Magnetic flux
|
Φ
|
Measure of magnetism, taking account of the strength and the extent of a magnetic field
|
weber (Wb)
|
L2 M T−2 I−1
|
scalar
|
Mass fraction
|
x
|
Mass of a substance as a fraction of the total mass
|
kg/kg
|
1
|
intensive
|
(Mass) Density (or volume density)
|
ρ
|
Mass per unit volume
|
kg/m3
|
L−3 M
|
intensive
|
Mean lifetime
|
τ
|
Average time for a particle of a substance to decay
|
s
|
T
|
intensive
|
Molar concentration
|
C
|
Amount of substance per unit volume
|
mol⋅m−3
|
L−3 N
|
intensive
|
Molar energy
|
J/mol
|
Amount of energy present in a system per unit amount of substance
|
J/mol
|
L2 M T−2 N−1
|
intensive
|
Molar entropy
|
S°
|
Entropy per unit amount of substance
|
J/(K⋅mol)
|
L2 M T−2 Θ−1 N−1
|
intensive
|
Molar heat capacity
|
c
|
Heat capacity of a material per unit amount of substance
|
J/(K⋅mol)
|
L2 M T−2 Θ−1 N−1
|
intensive
|
Moment of inertia
|
I
|
Inertia of an object with respect to angular acceleration
|
kg⋅m2
|
L2 M
|
extensive, tensor, scalar
|
Optical power
|
P
|
Measure of the effective curvature of a lens or curved mirror; inverse of focal length
|
dioptre (dpt = m−1)
|
L−1
|
|
Permeability
|
μs
|
Measure for how the magnetization of material is affected by the application of an external magnetic field
|
H/m
|
L M T−2 I−2
|
intensive
|
Permittivity
|
εs
|
Measure for how the polarization of a material is affected by the application of an external electric field
|
F/m
|
L−3 M−1 T4 I2
|
intensive
|
Plane angle
|
θ
|
Ratio of circular arc length to radius
|
radian (rad)
|
1
|
|
Power
|
P
|
Rate of transfer of energy per unit time
|
watt (W)
|
L2 M1 T−3
|
extensive, scalar
|
Pressure
|
p
|
Force per unit area
|
pascal (Pa = N/m2)
|
L−1 M1 T−2
|
intensive, scalar
|
(Radioactivity) Activity
|
A
|
Number of particles decaying per unit time
|
becquerel (Bq = Hz)
|
T−1
|
extensive, scalar
|
(Radiation) Dose
|
D
|
Ionizing radiation energy absorbed per unit mass
|
gray (Gy = J/kg)
|
L2 T−2
|
|
Radiance
|
L
|
Power of emitted electromagnetic radiation per unit solid angle per emitting source area
|
W/(m2⋅sr)
|
M T−3
|
|
Radiant intensity
|
I
|
Power of emitted electromagnetic radiation per unit solid angle
|
W/sr
|
L2 M T−3
|
scalar
|
Reaction rate
|
r
|
Rate of a chemical reaction for unit time
|
mol/(m3⋅s)
|
L−3 T−1 N
|
intensive, scalar
|
Refractive index
|
n
|
Factor by which the phase velocity of light is reduced in a medium
|
unitless
|
1
|
intensive, scalar
|
Reluctance
|
|
resistance to the flow of magnetic flux
|
H−1
|
L−2 M−1 T2 I2
|
scalar
|
Solid angle
|
Ω
|
Ratio of area on a sphere to its radius squared
|
steradian (sr)
|
∠2
|
|
Specific energy
|
|
Energy density per unit mass
|
J⋅kg−1
|
L2 T−2
|
intensive
|
Specific heat capacity
|
c
|
Heat capacity per unit mass
|
J/(K⋅kg)
|
L2 T−2 Θ−1
|
intensive
|
Specific volume
|
v
|
Volume per unit mass (reciprocal of density)
|
m3⋅kg−1
|
L3 M−1
|
intensive
|
Spin
|
S
|
Quantum-mechanically defined angular momentum of a particle
|
kg⋅m2⋅s−1
|
L2 M T−1
|
|
Strain
|
ε
|
Extension per unit length
|
unitless
|
1
|
|
Stress
|
σ
|
Force per unit oriented surface area
|
Pa
|
L−1 M T−2
|
order 2 tensor
|
Surface tension
|
γ
|
Energy change per unit change in surface area
|
N/m or J/m2
|
M T−2
|
|
Thermal conductance
|
κ (or) λ
|
Measure for the ease with which an object conducts heat
|
W/K
|
L2 M T−3 Θ−1
|
extensive
|
Thermal conductivity
|
λ
|
Measure for the ease with which a material conducts heat
|
W/(m⋅K)
|
L M T−3 Θ−1
|
intensive
|
Thermal resistance
|
R
|
Measure for the ease with which an object resists conduction of heat
|
K/W
|
L−2 M−1 T3 Θ
|
extensive
|
Thermal resistivity
|
Rλ
|
Measure for the ease with which a material resists conduction of heat
|
K⋅m/W
|
L−1 M−1 T3 Θ
|
intensive
|
Volume
|
V
|
Three dimensional extent of an object
|
m3
|
L3
|
extensive, scalar
|
Volumetric flow rate
|
Q
|
Rate of change of volume with respect to time
|
m3⋅s−1
|
L3 T−1
|
extensive, scalar
|
Wavelength
|
λ
|
Perpendicular distance between repeating units of a wave
|
m
|
L
|
|
Wavenumber
|
k
|
Repetency or spatial frequency: the number of cycles per unit distance
|
m−1
|
L−1
|
scalar
|
Work
|
W
|
Transferred energy
|
joule (J)
|
L2 M T−2
|
scalar
|
Young's modulus
|
E
|
Ratio of stress to strain
|
pascal (Pa = N/m2)
|
L−1 M T−2
|
scalar; assumes isotropic linear material
|
spring constant
|
k
|
k is the torsional constant (measured in N·m/radian), which characterizes the stiffness of the torsional spring or the resistance to angular displacement.
|
N/m
|
M T−2
|
scalar
|