Search results
Results from the WOW.Com Content Network
The SI comprises a coherent system of units of measurement starting with seven base units, which are the second (symbol s, the unit of time), metre (m, length), kilogram (kg, mass), ampere (A, electric current), kelvin (K, thermodynamic temperature), mole (mol, amount of substance), and candela (cd, luminous intensity). The system can ...
The kilogram, symbol kg, is the SI unit of mass. It is defined by taking the fixed numerical value of the Planck constant h to be 6.626 070 15 × 10 −34 when expressed in the unit J⋅s, which is equal to kg⋅m 2 ⋅s −1, where the metre and the second are defined in terms of c and Δν Cs. —
"The kilogram, symbol kg, is the SI unit of mass. It is defined by taking the fixed numerical value of the Planck constant h to be 6.626 070 15 × 10 −34 when expressed in the unit J s , which is equal to kg m 2 s −1 , where the metre and the second are defined in terms of c and ∆ ν Cs ."
The first group of metric units are those that are at present defined as units within the International System of Units (SI). In its most restrictive interpretation, this is what may be meant when the term metric unit is used. The unit one (1) is the unit of a quantity of dimension one. It is the neutral element of any system of units. [2]
Heat capacity per unit mass J/(K⋅kg) L 2 T −2 Θ −1: intensive Specific volume: v: Volume per unit mass (reciprocal of density) m 3 ⋅kg −1: L 3 M −1: intensive Spin: S: Quantum-mechanically defined angular momentum of a particle kg⋅m 2 ⋅s −1: L 2 M T −1: Strain: ε: Extension per unit length unitless 1: Stress: σ: Force per ...
The base unit in the International System of Units (SI) is the meter, defined as "the length of the path travelled by light in vacuum during a time interval of 1 ⁄ 299792458 seconds." [ 9 ] It is approximately equal to 1.0936 yd .
A unit derived from the base units is used for expressing quantities of dimensions that can be derived from the base dimensions of the system—e.g., the square metre is the derived unit for area, which is derived from length. These derived units are coherent, which means that they involve only products of powers of the base units, without any ...
Systems of units vary from country to country. Some of the different systems include the centimetre–gram–second, foot–pound–second, metre–kilogram–second systems, and the International System of Units, SI. Among the different systems of units used in the world, the most widely used and internationally accepted one is SI. The base SI ...