Measurement depends on standard values {measurement unit} {unit of measurement}.
All other units combine length, time, and mass units {fundamental unit}| {absolute unit}. The seven fundamental SI units are length {meter, length unit}, time {second, time unit}, mass {kilogram, mass}, electric current {ampere}, thermodynamic temperature {Kelvin, thermodynamic temperature}, substance amount {mole, particle number}, and light intensity {candela, light intensity}.
derived units
The 22 derived SI units are plane angle {radian, plane angle}, solid angle {steradian, angle}, force {newton}, pressure {pascal}, energy {joule}, power {watt}, temperature {Celsius, temperature}, electric charge {coulomb, electric charge}, electric potential {volt}, electric capacitance {farad}, electric resistance {ohm}, electric conductance {siemens}, magnetic flux {weber}, magnetic flux density {tesla}, magnetic inductance {henry}, light flux {lumen, light flux}, illuminance {lux}, frequency {hertz}, rates and radioactivity {becquerel, radioactivity rate}, radiation dose {gray} {sievert}, and catalytic activity {katal}.
If constants c, G, k are set equal to 1, so c = G = k = 1, all measurements are in centimeters or inverse centimeters {geometrized unit}|. Length uses cm, time uses cm^-1, and mass uses cm^5. The basis for geometrized units is that time and distance relate by constant light speed. Mass, time, and length relate, because photons have different energies at different frequencies, and time relates to frequency. Fundamental units can be velocity, expressed as centimeters per second, or time, expressed as seconds.
To convert unit to another unit {conversion of units} {unit conversion}, multiply original measurement by new-unit to original-unit ratio, obtained from reference books, to cancel original unit and leave new unit. For example, to convert meters to centimeters, (15 meters) * (100 centimeters/meters) = 1500 centimeters.
Unit systems {metric system}| can use meter for length, kilogram for mass, and second for time {meter-kilogram-second system} (MKS), or centimeter for length, gram for mass, and second for time {centimeter-gram-second system} (CGS).
World standard measurement system {Systeme Internationale} (SI) is metric system.
English measurement system {Imperial measure} is in USA.
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Date Modified: 2022.0225