Miles per hour be used to express the speed of delivery of a ball in sporting events such as cricket, tennis and baseball. Miles per hour Miles per hour (abbreviated mph, MPH or mi/h) is an imperial and United States customary unit of speed expressing the number of statute miles covered in one hour. It is used in the United States, United Kingdom and many Commonwealth nations, particularly in the Caribbean region. Speed limits and road traffic speeds are given in miles per hour in the following jurisdictions (elsewhere kilometers per hour are used): Road traffic speeds in other countries are indicated in
Speed speed in everyday usage is the kilometre per hour or, in the US and the UK, miles per hour. For air and marine travel the knot is commonly used. The fastest possible speed at which energy or information can travel, according to special relativity, is the speed of light in a vacuum "c" = metres per second (approximately or ). Matter cannot quite reach the speed of light, as this would require an infinite amount of energy. In relativity physics, the concept of rapidity replaces the classical idea of speed. Italian physicist Galileo Galilei is usually credited with being the