Search results
Results From The WOW.Com Content Network
List of physical quantities. This article consists of tables outlining a number of physical quantities. The first table lists the fundamental quantities used in the International System of Units to define the physical dimension of physical quantities for dimensional analysis. The second table lists the derived physical quantities.
The constants listed here are known values of physical constants expressed in SI units; that is, physical quantities that are generally believed to be universal in nature and thus are independent of the unit system in which they are measured. Many of these are redundant, in the sense that they obey a known relationship with other physical ...
For example, the coherent derived SI unit unit of velocity is the metre per second, with the symbol m/s. [1]: 139 The base and coherent derived units of the SI together form a coherent system of units (the set of coherent SI units). A useful property of a coherent system is that when the numerical values of physical quantities are expressed in ...
The other units of length and mass, and all units of area, volume, and derived units such as density were derived from these two base units. Mesures usuelles (French for customary measurements) were a system of measurement introduced as a compromise between the metric system and traditional measurements. It was used in France from 1812 to 1839.
Cartesian y-axis basis unit vector unitless kinetic energy: joule (J) wave vector: radian per meter (m −1) Boltzmann constant: joule per kelvin (J/K) wavenumber: radian per meter (m −1) stiffness: newton per meter (N⋅m −1) ^ Cartesian z-axis basis unit vector
The Avogadro constant, commonly denoted NA[1] or L, [2] is an SI defining constant with an exact value of 6.022 140 76 × 1023 mol−1 (reciprocal moles). [3][4] It is defined as the number of constituent particles (usually molecules, atoms, ions, or ion pairs) per mole (SI unit) and used as a normalization factor in the amount of substance in ...
The Planck constant, or Planck's constant, denoted by , [1] is a fundamental physical constant [1] of foundational importance in quantum mechanics: a photon's energy is equal to its frequency multiplied by the Planck constant, and the wavelength of a matter wave equals the Planck constant divided by the associated particle momentum.
The SI has special names for 22 of these coherent derived units (for example, hertz, the SI unit of measurement of frequency), but the rest merely reflect their derivation: for example, the square metre (m 2), the SI derived unit of area; and the kilogram per cubic metre (kg/m 3 or kg⋅m −3), the SI derived unit of density. The names of SI ...