Units of measurement

Units of measurements

In mechanics, there are several units of measurement commonly used to quantify different physical quantities. Here are some of the key units of measurement used in mechanics:


Meter (m): The fundamental unit of length in the International System of Units (SI). It is defined as the distance traveled by light in a vacuum during a specific time interval.

Kilometer (km): Equal to 1,000 meters.

Centimeter (cm): Equal to one-hundredth (1/100) of a meter.

Millimeter (mm): Equal to one-thousandth (1/1,000) of a meter.

Inch (in): A non-SI unit of length commonly used in some countries. One inch is approximately equal to 2.54 centimeters.

Foot (ft): A non-SI unit of length commonly used in the United States and some other countries that have not adopted the metric system. It is defined as 0.3048 meters, meaning that one foot is approximately equal to 0.3048 meters. The foot is subdivided into 12 inches, and there are 3 feet in a yard. The foot is primarily used in everyday measurements of height, distance, and building construction in countries that have not fully transitioned to the metric system.


Kilogram (kg): The fundamental unit of mass in the SI system. It is defined as the mass of the International Prototype of the Kilogram, a platinum-iridium cylinder kept at the International Bureau of Weights and Measures in France.

Gram (g): Equal to one-thousandth (1/1,000) of a kilogram.


Second (s): The fundamental unit of time in the SI system. It is defined as the duration of 9,192,631,770 oscillations of the radiation corresponding to the transition between two hyperfine levels of the cesium-133 atom.


Newton (N): The unit of force in the SI system. It is defined as the force required to accelerate a one-kilogram mass by one meter per second squared (1 N = 1 kg·m/s²).


Meter per second (m/s): The SI unit of velocity. It represents the displacement in meters divided by the time in seconds.


Meter per second squared (m/s²): The SI unit of acceleration. It represents the change in velocity per unit time.

Other units

These are just a few examples of the units of measurement used in mechanics. Depending on the specific physical quantity being measured, there are additional units such as energy (joule), power (watt), pressure (pascal), and many others that are commonly used in mechanics and related fields.

quiz: What unit belongs to SI?
Materials for this article were gathered from various public sources or written by riglab.org editors.
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