km/s

3.7

A speed equal to one kilometre per second

noun

: km/s

Radio waves propagate at around 300,000 km/s in a vacuum.

Examples

The spacecraft reached a speed of 10 km/s during reentry.
Some asteroids travel through space at thousands of km/s relative to Earth.
The car was moving at 120 km/s.
She ran at a speed of 5 km/s.
Radio waves propagate at around 300,000 km/s in a vacuum.
Some asteroids travel through space at thousands of km/s relative to Earth.
The spacecraft reached a speed of 10 km/s during reentry.

Synonyms

kilometers per second

vskm/s

4 4.1

A measure of speed that shows how many kilometers something moves in one second

is the abbreviated symbol form rather than spelled out

Surface Forms

km/s singular

km/s plural

Etymology

Km/s stands for 'kilometres per second' and shows how many kilometres you travel in one second. The kilo part means 'thousand', like in kilogram, m is short for metre, and /s means 'per second', so km/s literally tells you the distance covered each second and is used to measure speed.