SI units

SI Units

The International System of Units (SI, abbreviated from the French Système international (d'unités)) is the modern form of the metric system. It is the only system of measurement with an official status in nearly every country in the world.

History

The SI system was first proposed by the French Academy of Sciences in 1791. The idea was to create a universal system of measurement that could be used worldwide. The system was officially adopted in France in 1795 and has since been adopted by nearly every country in the world.

Units

The SI system is made up of seven base units: the metre (m), kilogram (kg), second (s), ampere (A), kelvin (K), mole (mol), and candela (cd). These units are used to measure length, mass, time, electric current, temperature, amount of substance, and luminous intensity, respectively.

Prefixes

In addition to the base units, the SI system also includes a set of prefixes that can be added to the base units to create multiples and submultiples of the original unit. These prefixes range from yotta (10^24) to yocto (10^-24).

Usage

The SI system is used in nearly every field of science and engineering. It is also used in everyday life in most countries, with the notable exception of the United States, which still uses the Imperial system for many measurements.

See also

• Metric system
• Imperial system
• United States customary units