Speed
From Wikipedia, the free encyclopedia.

For alternative meanings of Speed, see Speed (disambiguation).

Speed is the rate of motion expressed as distance moved per unit of time. Speed is a scalar quantity; the equivalent vector quantity is known as velocity.

Units of speed include:

• meter per second, (symbol m/s), the SI derived unit
• kilometer per hour, (symbol km/h)
• mile per hour, (symbol mph)
• knot (nautical miles per hour)
• Mach, where Mach 1 is the speed of sound; Mach n is n times as fast.

1 m/s = 3.6 km/h

1 mph = 1.609 km/h

1 knot = 1.852 km/h = 0.514 m/s

Mach 1 = about 1200 km/h = about 330 m/s

The original article can be found at: http://en.wikipedia.org/wiki/Speed.
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