Mile per hour (mph)

Definition

Mile per hour (mph) is a unit of speed commonly used in the United States and the United Kingdom. It measures the number of miles traveled in one hour. It is not an SI unit; the SI unit for speed is meters per second (m/s). One mile per hour is defined as exactly 0.44704 meters per second.

History

The mile itself has ancient roots, originating from the Roman "mille passus," or "a thousand paces." The mph unit gained prominence in the 19th century with the expansion of railroads. By the early 1900s, mph was widely adopted for road vehicles.

Uses

Mph is primarily used in the U.S. and the UK for speed limits on roads and signage. It is also employed in aviation and maritime contexts. In contrast, most other countries use kilometers per hour (km/h).

Conversions

  • 1 mph = 1.60934 kilometers per hour (km/h)
  • 1 mph = 0.44704 meters per second (m/s)
  • 1 mph = 5280 feet per minute (ft/min)

Fun Facts

  • A common misconception is that mph is a universal speed measurement; however, many countries use km/h.
  • The term "miles per hour" is often abbreviated as "mph" in speed limit signs and vehicle speedometers.
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