The kilometre (American spelling: kilometer), symbol km[1] is a unit of length in the metric system, equal to one thousand metres and is therefore exactly equal to the distance travelled by light in free space in 1⁄ 299,792.458 of a second.[2]
It is the conventionally used measurement unit for expressing distances between geographical places in countries which use the metric system. While it is defined exactly as 1000 m, it equals roughly a ten minutes' walk.
Slang terms for kilometre include click (sometimes spelled klick or klik) and kay (or k).[3][4] [5] [6]
Contents |
|
