kilometre per second is an SI derived unit of both speed (scalar) and velocity (vector), signified by the symbol km/s or km s^{-1}. It is equal to 1,000 m/s.

1 km/s is about the top speed of a sub-orbital spacecraft.

A corresponding unit of area is the square kilometre and a corresponding unit of volume is the cubic kilometre.

In English, the word "kilometre" is often pronounced with the stress on the second syllable, unlike other SI units (such as kilogram) where the stress is placed on the first syllable.

Virtually all countries of the world utilise the kilometre as a standard measure of distance, particularly on road network signage to indicate distances to cities, towns, villages and suburbs etc. The USA is gradually kilometerising its road signage in many states.

Metre persecond (U.S. spelling: meter persecond) is an SI derived unit of both speed (scalar) and velocity (vector quantity which specifies both magnitude and a specific direction), defined by distance in metres divided by time in seconds.

Astronomical measurements sometimes list velocities in terms of kilometrespersecond, where a kilometrepersecond is equivalent to 1 000 metres persecond.

Although m/s is considered as a derived unit, it could be viewed as more fundamental than the metre, since the latter is defined through the speed of light in the vacuum, taken to be exactly 299792458 m/s by definition, which then gives the metre using the definition of one second.

Share your thoughts, questions and commentary here

Want to know more? Search encyclopedia, statistics and forums:

Press Releases |
Feeds |
Contact
The Wikipedia article included on this page is licensed under the
GFDL.
Images may be subject to relevant owners' copyright.
All other elements are (c) copyright NationMaster.com 2003-5. All Rights Reserved.
Usage implies agreement with terms, 1022, m