# List of physical quantities

## List of physical quantities

Note that the dimensions chosen as the primary dimensions is arbitrary and dependent upon the choice of units used. The dimensional analysis here is based on the base units of the International System of Units. Other dimensions such as force [F] rather than mass [M], or charge [Q] rather than current [I], could be used. Even the number of dimensions used is not a fixed, invariable number. In a three-base unit cgs system, for example, the units of charge are erg½ cm½ and the dimensional analysis of this quantity in terms of the quantities represented by the base units is [M]½ [L] [T]-1, whereas in the analysis below charge has units of [I] [T]. Also note that the symbols are not International Standards and may be used differently than shown here. However, these symbols are often used in the science community.

 Base Physical Quantity Symbol Meaning Dimensions in SI SI unit Length l The one dimensional extent of an object L metre (m) Mass m The amount of matter in an object M kilogram (kg) Time t The duration of an event T second (s) Current I The rate of flow of electrical charge I ampere (A) Temperature T . Θ kelvin (K) Amount of substance n Number of particles compared to number of atoms in 0.012 kg C12 ... mol (mol) Luminous intensity L ... candela (cd) Derived Physical Quantity Symbol Meaning Dimensions SI unit Area A The two dimensional extent of an object L2 square metre Angle θ . one radian (rad) Solid angle . . one steradian (sr) Volume V The three dimensional extent of an object L3 cubic metre Linear density ρl The amount of mass per unit length of a 1-dimensional object M L-1 kilogram per metre Area density ρA The amount of mass per unit area of a 2-dimensional object M L-2 kilogram per square metre (Volume) Density ρ The amount of mass per unit volume of a 3-dimensional object M L-3 kilogram per cubic metre Speed v The rate of change of position of an object L T-1 metre per second Acceleration a The rate of change of speed of an object L T-2 metre per second squared Momentum p The product of an object's mass and its velocity M L T-1 kilogram metre per second or newton second Impulse p The product of a force and the time over which it acts M L T-1 kilogram metre per second or newton second Force F That which causes or tends to cause acceleration in an object with mass M L T-2 newton = kilogram metre per second squared Work W The energy dissipated by a force moving through a distance, and calculated from the product of the force and the distance moved in the direction of the force M L2 T-2 joule = newton metre Energy E The capacity of a body or system to do work M L2 T-2 joule = newton metre Kinetic energy Ek The energy that a body possesses by virtue of its speed or velocity M L2 T-2 joule = newton metre Potential energy Ep The energy that a body possesses by virtue of its position in a potential field M L2 T-2 joule = newton metre Power P The rate of change of energy over time M L2 T-3 watt = joule per second Pressure p The amount of force per unit area M L-1 T-2 pascal = newton per square metre Electric Charge Q . I T coulomb = ampere second Moment . . ? . Torque T . M L2 T-2 newton metre Phase angle . . one radian Wavelength λ . L metre Frequency f . T-1 hertz Angular speed . . T-1 radian per second Angular velocity . . T-1 radian per second Angular acceleration . . T-2 radian per second squared Moment of inertia I . M L2 kilogram metre squared Area moment of inertia . . L4 Angular momentum . . ? . Rotational energy or Angular kinetic energy . . ? . Magnetic flux . measure of quantity of magnetism, taking account of the strength and the extent of a magnetic field M T-2 I-1 tesla

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