Search results
Results from the WOW.Com Content Network
1.6 × 10 −5 quectometers (1.6 × 10 −35 meters) – the Planck length (Measures of distance shorter than this do not make physical sense, according to current theories of physics.) 1 qm – 1 quectometer, the smallest named subdivision of the meter in the SI base unit of length, one nonillionth of a meter. [55]
In the SI system and generally in older metric systems, multiples and fractions of a unit can be described via a prefix on a unit name that implies a decimal (base-10), multiplicative factor. The only exceptions are for the SI-accepted units of time (minute and hour) and angle (degree, arcminute, arcsecond) which, based on ancient convention ...
A unit of measurement, or unit of measure, is a definite magnitude of a quantity, defined and adopted by convention or by law, that is used as a standard for measurement of the same kind of quantity. [1] Any other quantity of that kind can be expressed as a multiple of the unit of measurement. [2] For example, a length is a physical quantity.
Name of unit Symbol Definition Relation to SI units spat: ≡ 4π sr [16] – The solid angle subtended by a sphere at its centre. ≈ 12.566 37 sr: square degree: deg 2; sq.deg.; (°) 2: ≡ (π ⁄ 180) 2 sr: ≈ 0.304 62 × 10 −3 sr: steradian (SI unit) sr The solid angle subtended at the center of a sphere of radius r by a portion of the ...
The base units and the derived units formed as the product of powers of the base units with a numerical factor of one form a coherent system of units. Every physical quantity has exactly one coherent SI unit. For example, 1 m/s = (1 m) / (1 s) is the coherent derived unit for velocity.
Conversion of units is the conversion of the unit of measurement in which a quantity is expressed, typically through a multiplicative conversion factor that changes the unit without changing the quantity. This is also often loosely taken to include replacement of a quantity with a corresponding quantity that describes the same physical property.
The basic unit of length in the imperial and U.S. customary systems is the yard, defined as exactly 0.9144 m by international treaty in 1959. [2] [10] Common imperial units and U.S. customary units of length include: [11] thou or mil (1 ⁄ 1000 of an inch) inch (25.4 mm) foot (12 inches, 0.3048 m) yard (3 feet, 0.9144 m)
The nanometre (international spelling as used by the International Bureau of Weights and Measures; SI symbol: nm), or nanometer (American spelling), is a unit of length in the International System of Units (SI), equal to one billionth (short scale) or one thousand million (long scale) of a meter (0.000000001 m) and to 1000 picometres.