SI derived unit m), the SI derived unit of density. The names of SI derived units, when written in full, are in lowercase. However, the symbols for units named after persons are written with an uppercase initial letter. For example, the symbol for hertz is "Hz"; but the symbol for metre is "m". The International System of Units assigns special names to 22 derived units, which includes two dimensionless derived units, the radian (rad) and the steradian (sr). Some other units such as the hour, litre, tonne, bar and electronvolt are not SI units, but are widely used in conjunction with SI units.
Metre per second Metre per second Metre per second (American English: meter per second) 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. The SI unit symbols are m·s, m s, m/s, or , sometimes (unofficially) abbreviated as . Where metres per second are several orders of magnitude too slow to be convenient, such as in astronomical measurements, velocities may be given in kilometres per second, where is 1000 metres per second, sometimes unofficially abbreviated as "kps". is equivalent to: 1