Geographical mile longitude at the equator is thus exactly 60 geographical miles. It was closely related to the nautical mile, which was originally determined as 1 minute of arc along a great circle of the Earth, but is nowadays defined as exactly 1852 metres. The US National Institute of Standards and Technology (NIST) notes that: "The international nautical mile of 1 852 meters (6 076.115 49...feet) was adopted effective July 1, 1954, for use in the United States. The value formerly used in the United States was 6 080.20 feet = 1 nautical (geographical or sea) mile." (6080.2 feet is 1853.24496 meters.)
Slug (unit) Slug (unit) The slug is a derived unit of mass in the weight-based system of measures, most notably within the British Imperial measurement system and in the United States customary measures system. Systems of measure either define mass and derive force or define a base force and derive a mass unit. A slug is defined as the mass that is accelerated by 1 ft/s when a force of one pound (lbf) is exerted on it. One slug has a mass of based on standard gravity, the international foot, and the avoirdupois pound. At the Earth's surface, an object with a