Base Units of the SI System [MEMORIZE]

Base Units of the SI System, the properties measured, name of the unit and its symbol.

Property Measured: length

meter (m). The standard unit of length in both the SI and metric systems is the meter (m).

Property Measured: mass

kilogram (kg). The standard unit of mass in the SI system is the kilogram (kg). (Kilo = Greek word for “thousand”).

Property Measured: time

second (s). The SI base unit of time is the second(s).

Property Measured: temperature

kelvin (K) (written in all lowercase except for its symbol). The SI unit of temperature is the kelvin (K). (Do NOT add the word degree nor the degree symbol when using kelvin (K)).

Property Measured: electric current

ampere (A).

Property Measured: amount of substance

mole (mol).

Property Measured: luminous intensity

candela (cd).

Derived Unit

A derived unit is a unit that does not show up on the metric or SI system. EX: m³, cubic meters which is used for the volume. By definition, a derived unit is a measurement that is created by combining two or more base units through mathematical operations like multiplication or division. EX: speed, like meters per second m/s, is a derived unit because it combines the base units of length (meter) and time (second).

Derived Unit for Density

kilograms per cubic meter (kg/m³).

Derived Unit for Volume

cubic meter (m³) and/or liter (L).

Derived Unit for Area

square meter (m²).

Derived Unit for Speed

meters per second (m/s). Unlike time, in which you use seconds, speed is a measure of distance over time, hence meters per second (m/s).