Meter (m)

Definition

A meter (m) is the base unit of length in the International System of Units (SI). It is defined as the distance light travels in a vacuum in 1/299,792,458 seconds.

5 Must Know Facts For Your Next Test

1. The meter was originally defined by the French Academy of Sciences as one ten-millionth of the distance from the equator to the North Pole along a meridian through Paris.
2. In 1960, the definition was revised to be based on a specific number of wavelengths of light emitted by krypton-86.
3. The current definition, based on the speed of light, was adopted in 1983 by the General Conference on Weights and Measures.
4. One meter is equivalent to 100 centimeters or 1,000 millimeters.
5. The meter is used globally in scientific measurements and most everyday applications outside of countries like the United States which primarily use feet and inches.

Review Questions

Related terms

Centimeter (cm): A centimeter is a unit of length equal to one-hundredth (1/100) of a meter.

Millimeter (mm): A millimeter is a unit of length equal to one-thousandth (1/1000) of a meter.

Speed of Light: $c$ represents the speed at which light travels in vacuum, precisely $299,792,458$ meters per second.