Meter
Definition1
The distance that light travels in $\dfrac{1}{299\ 792\ 458}$ seconds in a vacuum is defined as $1$ meters, and it is denoted by $\text{m}$.
Explanation
Conversely, the speed of light $c$ is $299\ 792\ 458$ meters per second. This is an exact figure, not an approximation.
$$ c = 299\ 792\ 458\ \text{m/s} $$
It is the most popular unit of length and one of the SI base units.
| Measurement | Name | Symbol |
|---|---|---|
| Length | Meter | m |
| Mass | Kilogram | kg |
| Time | Second | s |
| Current | Ampere | A |
| Temperature | Kelvin | K |
| Substance | Mole | mol |
| Luminous | Candela | cd |