Plane angle 
θ 
Measure of a change in direction or orientation. 
radian (rad) 
1 

Solid angle 
Ω 
Measure of the size of an object as projected on a sphere. 
steradian (sr) 
1 

Absorbed dose rate 

Absorbed dose received per unit of time. 
Gy s^{−1} 
L^{2}T^{−3} 

Acceleration 
a→ 
Rate of change of the speed or velocity of an object. 
m s^{−2} 
L T^{−2} 
vector 
Angular acceleration 
α 
Rate of change in angular speed or velocity. 
rad s^{−2} 
T^{−2} 

Angular speed (or angular velocity) 
ω 
The angle incremented in a plane by a segment connecting an object and a reference point per unit time. 
rad s^{−1} 
T^{−1} 
scalar or pseudovector 
Angular momentum 
L 
Measure of the extent and direction an object rotates about a reference point. 
kg m^{2} s^{−1} 
M L^{2}T^{−1} 
conserved quantity, pseudovector 
Area 
A 
The twodimensional extent of an object. 
m^{2} 
L^{2} 
scalar 
Area density 
ρ_{A} 
The amount of mass per unit area of a twodimensional object. 
kg m^{−2} 
M L^{−2} 

Capacitance 
C 
Measure for the amount of stored charge for a given potential. 
farad (F = A^{2} s^{4} kg^{−1} m^{−2}) 
I^{2}T^{4}M^{−1}L^{−2} 
scalar 
Catalytic activity 

Change in reaction rate due to presence of a catalyst. 
katal (kat = mol s^{−1}) 
N T^{−1} 

Catalytic activity concentration 

Change in reaction rate due to presence of a catalyst per unit volume of the system. 
kat m^{−3} 
N L^{−3}T^{−1} 

Chemical potential 
μ 
The amount of energy needed to add a particle to a system. 
J mol^{−1} 
M L^{2}T^{−2}N^{−1} 
intensive 
Molar concentration 
C 
Amount of substance per unit volume. 
mol m^{−3} 
N L^{−3} 
intensive 
Crackle 
c→ 
Rate of change of Jounce. The fifth derivative of position. 
m s^{−5} 
L T^{−5} 
Vector 
Current density 
J → 
Amount of electric current flowing through a surface. 
A m^{−2} 
I L^{−2} 
vector 
Dose equivalent 
H 
Measure for the received amount of radiation adjusted for the effect of different types of radiant on biological tissue. 
sievert (Sv = m^{2} s^{−2}) 
L^{2}T^{−2} 

Dynamic Viscosity 
η 
Measure for the resistance of an incompressible fluid to stress. 
Pa s 
M L^{−1}T^{−1} 

Electric Charge 
Q 
Amount of electric charge. 
coulomb (C = A s) 
I T 
extensive, conserved quantity 
Electric charge density 
ρ_{Q} 
Amount of electric charge per unit volume. 
C m^{−3} 
I T L^{−3} 
intensive 
Electric displacement 
D 
Strength of the electric displacement. 
C m^{−2} 
I T L^{−2} 
vector field 
Electric field strength 
E→ 
Strength of the electric field. 
V m^{−1} 
M L T^{−3}I^{−1} 
vector field 
Electrical conductance 
G 
Meausure for how easily current flows through a material. 
siemens (S = A^{2} s^{3} kg^{−1} m^{−2}) 
L^{−2}M^{−1}T^{3}I^{2} 
scalar 
Electric potential 
V 
The amount of work required to bring a unit charge into an electric field from infinity. 
volt (V = kg m^{2} A^{−1} s^{−3}) 
L^{2}M T^{−3}I^{−1} 
scalar 
Electrical resistance 
R 
The degree to which an object opposes the passage of an electric current. 
ohm (Ω = kg m^{2} A^{−2} s^{−3}) 
L^{2}M T^{−3}I^{−2} 
scalar 
Energy 
E 
The capacity of a body or system to do work. 
joule (J = kg m^{2} s^{−2}) 
M L^{2}T^{−2} 
extensive, scalar, conserved quantity 
Energy density 
ρ_{E} 
Amount of energy per unit volume. 
J m^{−3} 
M L^{−1}T^{−2} 
intensive 
Entropy 
S 
Measure for the amount of available states for a system. 
J K^{−1} 
M L^{2}T^{−2}Θ^{−1} 
extensive, scalar 
Force 
F→ 
The cause of acceleration, acting on an object. 
newton (N = kg m s^{−2}) 
M L T^{−2} 
vector 
Fuel efficiency 

Distance traveled per meter cubed. 

L^{−2} 
scalar 
Impulse 
p→ 
The cause of a change in momentum, acting on an object. 
kg m s^{−1} 
M L T^{−1} 
vector 
Frequency 
f 
The number of times something happens in a period of time. 
hertz (Hz =s^{−1}) 
T^{−1} 
scalar 
Halflife 
t_{1/2} 
The time needed for a quantity to decay to half its original value. 
s 
T 

Heat 
Q 
Amount of energy transferred between systems due to temperature difference. 
J 
M L^{2}T^{−2} 

Heat capacity 
C_{p} 
Amount of energy needed to raise the temperature of a system by one degree. 
J K^{−1} 
M L^{2}T^{−2}Θ^{−1} 
extensive 
Heat flux density 
ϕ_{Q} 
Amount of heat flowing through a surface per unit area. 
W m^{−2} 
M T^{−3} 

Illuminance 
E_{v} 
Total luminous flux incident to a surface per unit area. 
lux (lx = cd sr m^{−2}) 
J L^{−2} 

Impedance 
Z 
Measure for the resistance of an electrical circuit against an alternating current. 
ohm (Ω = kg m^{2} A^{−2} s^{−3}) 
M'L'^{2}T^{−3}I^{−2} 
complex scalar 
Index of refraction 
n 
The factor by which the speed of light is reduced in a medium. 

1 
intensive, scalar 
Inductance 
L 
Measure for the amount of magnetic flux generated for a certain current run through a circuit. 
henry (H = kg m^{2} A^{−2} s^{−2}) 
M L^{2}T^{−2}I^{−2} 
scalar 
Irradiance 
E 
Power of electromagnetic radiation flowing through a surface per unit area. 
W m^{−2} 
M T^{−3} 

Intensity 
I 
Power per unit cross sectional area. 
W m^{−2} 
M T^{−3} 

Jerk 
j→ 
Rate of change of acceleration. The third derivative of position. 
m s^{−3} 
L T^{−3} 
Vector 
Jounce (or snap) 
s→ 
Rate of change of Jerk. The fourth derivative of position. 
m s^{−4} 
L T^{−4} 
Vector 
Linear density 
ρ_{l} 
Amount of mass per unit length of a onedimensional object. 

M L^{−1} 

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 (M = u/c) 
1 

Magnetic field strength 
H 
Strength of a magnetic field in a material. 
A m^{−1} 
I L^{−1} 
vector field 
Magnetic flux 
Φ 
Measure of quantity of magnetism, taking account of the strength and the extent of a magnetic field. 
weber (Wb = kg m^{2} A^{−1} s^{−2}) 
M L^{2}T^{−2}I^{−1} 
scalar 
Magnetic flux density 
B 
Measure for the strength of the magnetic field. 
tesla (T = kg A^{−1} s^{−2}) 
M T^{−2}I^{−1} 
pseudovector field 
Magnetization 
M 
Amount of magnetic moment per unit volume. 
A m^{−1} 
I L^{−1} 
vector field 
Mass fraction 
x 
Mass of a substance as a fraction of the total mass. 
kg/kg 
1 
intensive 
(Mass) Density (or volume density) 
ρ 
The amount of mass per unit volume of a threedimensional object. 
kg m^{−3} 
M L^{−3} 
intensive 
Mean lifetime 
τ 
Average time needed for a particle to decay. 
s 
T 
intensive 
Molar energy 

Amount of energy present is a system per unit amount of substance. 
J mol^{−1} 
M L^{2}T^{−2}N^{−1} 
intensive 
Molar entropy 

Amount of entropy present in a system per unit amount of substance. 
J K^{−1} mol^{−1} 
M L^{2}T^{−2}Θ^{−1}N^{−1} 
intensive 
Molar heat capacity 
c 
Heat capacity of a material per unit amount of substance. 
J K^{−1} mol^{−1} 
M L^{2}T^{−2}N^{−1} 
intensive 
Moment of inertia 
I 
Inertia of an object with respect to angular acceleration. 
kg m^{2} 
M L^{2} 
tensor, scalar 
Momentum 
p→ 
Product of an object's mass and velocity. 
N s 
M L T^{−1} 
vector, extensive 
Permeability 
μ 
Measure for how the magnetization of material is affected by the application of an external magnetic field. 
H m^{−1} 
M L T^{−2}I^{−2} 
intensive 
Permittivity 
ε 
Measure for how the polarization of a material is affected by the application of an external electric field. 
F m^{−1} 
I^{2}M^{−1}L^{−3}T^{4} 
intensive 
Power 
P 
The rate of change in energy over time. 
watt (W) 
M L^{2}T^{−3} 
extensive, scalar 
Pressure 
p 
Amount of force per unit area. 
pascal (Pa = kg m^{−1} s^{−2}) 
M L^{−1}T^{−2} 
intensive, scalar 
Pop 
p→ 
Rate of change of crackle. The sixth derivative of position. 
m s^{−6} 
L T^{−6} 
Vector 
(Radioactive) Activity 
A 
Number of particles decaying per unit time. 
becquerel (Bq = s^{−1}) 
T^{−1} 
extensive, scalar 
(Radioactive) Dose 
D 
Amount of energy absorbed by biological tissue from ionizing radiation per unit mass. 
gray (unit) (Gy = m^{2} s^{−2}) 
L^{2}T^{−2} 

Radiance 
L 
Power of emitted electromagnetic radiation per solid angle and per projected source area. 
W m^{−2} sr^{−1} 
M T^{−3} 

Radiant intensity 
I 
Power of emitted electromagnetic radiation per solid angle. 
W sr^{−1} 
M L^{2}T^{−3} 
scalar 
Reaction rate 
r 
Measure for speed of a chemical reaction. 
mol m^{−3} s^{−1} 
N L^{−3}T^{−1} 
intensive, scalar 
Refractive Index 
n 
Measure of how light is refracted through a medium. 
Unitless 
Dimensionless 

Angle 
θ 
The space between two intersecting lines at or close to the point where they meet. 
rad / Degree 
Dimensionless 

Speed 
v 
Rate of change of the position of an object. 
m s^{−1} 
L T^{−1} 
scalar 
Specific energy 

Amount of energy present per unit mass. 
J kg^{−1} 
L^{2}T^{−2} 
intensive 
Specific heat capacity 
c 
Heat capacity per unit mass. 
J kg^{−1} K^{−1} 
L^{2}T^{−2}Θ^{−1} 
intensive 
Specific volume 
v 
The volume occupied by a unit mass of material (reciprocal of density). 
m^{3} kg^{−1} 
L^{3}M^{−1} 
intensive 
Spin 
S 
Intrinsic property of particles, roughly to be interpreted as the intrinsic angular momentum of the particle. 
kg m^{2} s^{−1} 
M L^{2}T^{−1} 

Strain 

Extension per unit length. 
Unitless 
Dimensionless 

Stress 
σ 
Amount of force exerted per surface area. 
Pa 
M L^{−1}T^{−2} 
2tensor. (or scalar) 
Surface tension 
γ 
Amount of work needed to change the surface of a liquid by a unit surface area. 
N m^{−1} or J m^{−2} 
M T^{−2} 

Thermal conductivity 
k 
Measure for the ease with which a material conducts heat. 
W m^{−1} K^{−1} 
M L T^{−3}Θ^{−1} 
intensive 
Torque 
τ 
Product of a force and the perpendicular distance of the force from the point about which it is exerted. 
N m 
M L^{2}T^{−2} 
pseudovector 
Velocity 
v→ 
Speed of an object in a chosen direction. 
m s^{−1} 
L T^{−1} 
vector 
Volume 
V 
The three dimensional extent of an object. 
m^{3} 
L^{3} 
extensive, scalar 
Wavelength 
λ 
Distance between repeating units of a propagating wave. 
m 
L 

Wavenumber 
k 
Reciprocal of the wavelength. 
m^{−1} 
L^{−1} 

Weight 
w 
Amount of gravitation force exerted on an object. 
newton (N = kg m s^{−2}) 
M L T^{−2} 
vector 
Work 
W 
Energy dissipated by a force moving over a distance, scalar product of the force and the movement vector. 
joule (J = kg m^{2} s^{−2}) 
M L^{2}T^{−2} 
scalar 
Young's modulus 
ε 
Ratio of Stress over Strain. 
pascal (Pa = kg m^{−1} s^{−2}) 
M L^{−1}T^{−2} 
scalar 
Absement 
A 
Measure of sustained displacement; the first integral of displacement. 
m s 
LT 
vector 
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