Foot/second (fps)
Definition: A foot per second (symbol: fps or ft/s) is a unit of speed in the imperial and US customary systems. It is defined as the speed of an object traveling one foot in one second.
History/origin: The foot per second has been used as a unit of speed since the 19th century. It is based on the foot, which was originally defined as the length of a human foot.
Current use: The foot per second is primarily used in the United States and United Kingdom for measuring the speed of objects in various applications, including physics and engineering.
Mile/hour (mph)
Definition: A mile per hour (symbol: mph or mi/h) is a unit of speed in the imperial and US customary systems. It is defined as the speed of an object traveling one mile in one hour.
History/origin: The mile per hour has been used as a unit of speed since the 19th century. It is based on the mile, which was originally defined as 5,280 feet.
Current use: The mile per hour is primarily used in the United States and United Kingdom for measuring vehicle speeds and speed limits.