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Unit Of Length
A unit of length refers to any arbitrarily chosen and accepted reference standard for measurement of length. The most common units in modern use are the metric units, used in every country globally. In the United States the U.S. customary units are also in use. British Imperial units are still used for some purposes in the United Kingdom and some other countries. The metric system is sub-divided into SI and non-SI units. Metric system SI The base unit in the International System of Units (SI) is the metre, defined as "the length of the path travelled by light in vacuum during a time interval of seconds." It is approximately equal to . Other SI units are derived from the metre by adding prefixes, as in millimetre or kilometre, thus producing systematic decimal multiples and submultiples of the base unit that span many orders of magnitude. For example, a kilometre is . Non-SI In the centimetre–gram–second system of units, the basic unit of length is the centimetre, or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Measurement Unit
A unit of measurement is a definite magnitude of a quantity, defined and adopted by convention or by law, that is used as a standard for measurement of the same kind of quantity. Any other quantity of that kind can be expressed as a multiple of the unit of measurement. For example, a length is a physical quantity. The metre (symbol m) is a unit of length that represents a definite predetermined length. For instance, when referencing "10 metres" (or 10 m), what is actually meant is 10 times the definite predetermined length called "metre". The definition, agreement, and practical use of units of measurement have played a crucial role in human endeavour from early ages up to the present. A multitude of systems of units used to be very common. Now there is a global standard, the International System of Units (SI), the modern form of the metric system. In trade, weights and measures is often a subject of governmental regulation, to ensure fairness and transparency. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
X Unit
: ''For the software testing tools, see xUnit.'' The x unit (symbol xu) is a unit of length approximately equal to 0.1 pm (10−13 m). It is used to quote the wavelength of X-rays and gamma rays. Originally defined by the Swedish physicist Manne Siegbahn (1886–1978) in 1925, the x unit could not at that time be measured directly; the definition was instead made in terms of the spacing between planes of the calcite crystals used in the measuring apparatus. One x unit was set at of the spacing of the (200) planes of calcite at 18 °C. In modern usage, there are two separate x units, which are defined in terms of the wavelengths of the two most commonly used X-ray lines in X-ray crystallography: * the copper x unit (symbol xu(Cu Kα1)) is defined so that the wavelength of the Kα1 line of copper is exactly 1537.400 xu(Cu Kα1); * the molybdenum x unit (symbol xu(Mo Kα1)) is defined so that the wavelength of the Kα1 line of molybdenum is exactly 707.831 xu(Mo Kα1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chain (unit)
The chain is a unit of length equal to 66 feet (22 yards). It is subdivided into 100 links (PDF) or 4 rods. There are 10 chains in a furlong, and 80 chains in one statute mile. In metric terms, it is 20.1168 m long. By extension, chainage (running distance) is the distance along a curved or straight survey line from a fixed commencing point, as given by an odometer. The chain has been used for several centuries in England and in some other countries influenced by English practice. In the United Kingdom, there were 80 chains to the mile, but until the early nineteenth century the Scottish and Irish customary miles were longer than the statute mile; consequently a Scots chain was about 74 (imperial) feet, an Irish chain 84 feet. These longer chains became obsolete following the adoption of the imperial system of units in 1824. Definition The UK statute chain is 22 yards, which is . This unit is a statute measure in the United Kingdom, defined in the Weights and Measures Act 19 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Surveying
Surveying or land surveying is the technique, profession, art, and science of determining the terrestrial two-dimensional or three-dimensional positions of points and the distances and angles between them. A land surveying professional is called a land surveyor. These points are usually on the surface of the Earth, and they are often used to establish maps and boundaries for ownership, locations, such as the designed positions of structural components for construction or the surface location of subsurface features, or other purposes required by government or civil law, such as property sales. Surveyors work with elements of geodesy, geometry, trigonometry, regression analysis, physics, engineering, metrology, programming languages, and the law. They use equipment, such as total stations, robotic total stations, theodolites, GNSS receivers, retroreflectors, 3D scanners, LiDAR sensors, radios, inclinometer, handheld tablets, optical and digital levels, subsurface locators, d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Determination Of The Rute And The Feet In Frankfurt
Determination is a positive emotional feeling that involves persevering towards a difficult goal in spite of obstacles.Kirby, L.D., Morrow, J., & Yih, J. (2014). The challenge of challenge: Pursuing determination as an emotion. In M. M. Tugade, M. N. Shiota, & L. D. Kirby (Eds.), Handbook of Positive Emotions. New York: Guilford Publications, Inc.Smith, C. A. (1991). The self, appraisal, and coping. In C. R. Snyder & D. R. Forsyth (Eds.), Handbook of Social and Clinical Psychology: The Health Perspective. New York: Pergamon press. Determination occurs prior to goal attainment and serves to motivate behavior that will help achieve one's goal. Empirical research suggests that people consider determination to be an emotion; in other words, determination is not just a cognitive state, but rather an affective state. In the psychology literature, researchers have studied determination under other terms, including challenge and anticipatory enthusiasm; this may explain one reason for th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pilot (aeronautics)
An aircraft pilot or aviator is a person who controls the flight of an aircraft by operating its directional flight controls. Some other aircrew members, such as navigators or flight engineers, are also considered aviators, because they are involved in operating the aircraft's navigation and engine systems. Other aircrew members, such as drone operators, flight attendants, mechanics and ground crew, are not classified as aviators. In recognition of the pilots' qualifications and responsibilities, most militaries and many airlines worldwide award aviator badges to their pilots. History The first recorded use of the term ''aviator'' (''aviateur'' in French) was in 1887, as a variation of ''aviation'', from the Latin ''avis'' (meaning ''bird''), coined in 1863 by in ''Aviation Ou Navigation Aérienne'' ("Aviation or Air Navigation"). The term ''aviatrix'' (''aviatrice'' in French), now archaic, was formerly used for a female aviator. These terms were used more in the earl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nautical Mile
A nautical mile is a unit of length used in air, marine, and space navigation, and for the definition of territorial waters. Historically, it was defined as the meridian arc length corresponding to one minute ( of a degree) of latitude. Today the international nautical mile is defined as exactly . The derived unit of speed is the knot, one nautical mile per hour. Unit symbol There is no single internationally agreed symbol, with several symbols in use. * M is used as the abbreviation for the nautical mile by the International Hydrographic Organization. * NM is used by the International Civil Aviation Organization. * nmi is used by the Institute of Electrical and Electronics Engineers and the United States Government Publishing Office. * nm is a non-standard abbreviation used in many maritime applications and texts, including U.S. Government Coast Pilots and Sailing Directions. It conflicts with the SI symbol for nanometre. History The word mile is from the Latin word ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fathom
A fathom is a unit of length in the imperial and the U.S. customary systems equal to , used especially for measuring the depth of water. The fathom is neither an International Standard (SI) unit, nor an internationally-accepted non-SI unit. Historically, however, it is the most frequently employed maritime measure of depth in the English-speaking world. There are two yards (6 feet) in an imperial fathom. Originally the span of a man's outstretched arms, the size of a fathom has varied slightly depending on whether it was defined as a thousandth of an (Admiralty) nautical mile or as a multiple of the imperial yard. Formerly, the term was used for any of several units of length varying around . Name The name (pronounced ) derives from the Old English word ''fæðm'', cognate to the Danish (via the Vikings) word "favn" meaning embracing arms or a pair of outstretched arms. Cognate maybe also via the Old High German word "fadum" of the same meaning.''Oxford English Dictionary' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sailor
A sailor, seaman, mariner, or seafarer is a person who works aboard a watercraft as part of its crew, and may work in any one of a number of different fields that are related to the operation and maintenance of a ship. The profession of the sailor is old, and the term ''sailor'' has its etymological roots in a time when sailing ships were the main mode of transport at sea, but it now refers to the personnel of all watercraft regardless of the mode of transport, and encompasses people who operate ships professionally, be it for a military navy or civilian merchant navy, as a sport or recreationally. In a navy, there may be further distinctions: ''sailor'' may refer to any member of the navy even if they are based on land; while ''seaman'' may refer to a specific enlisted rank. Professional mariners Seafarers hold a variety of professions and ranks, each of which carries unique responsibilities which are integral to the successful operation of an ocean-going vessel. A ship's c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
League (unit)
A league is a unit of length. It was common in Europe and Latin America, but is no longer an official unit in any nation. Derived from an ancient Celtic unit and adopted by the Romans as the ''leuga'', the league became a common unit of measurement throughout western Europe. It may have originally represented, roughly, the distance a person could walk in an hour. Since the Middle Ages, many values have been specified in several countries. Different definitions Ancient Rome The league was used in Ancient Rome, defined as 1½ Roman miles (7,500 Roman feet, modern 2.2 km or 1.4 miles). The origin is the ''leuga Gallica'' ''(also: leuca Callica)'', the league of Gaul. Argentina The Argentine league (''legua'') is or 6,666 ''varas'': 1 ''vara'' is . English-speaking world On land, the league is most commonly defined as three miles (4.83km), though the length of a mile could vary from place to place and depending on the era. At sea, a league is . English usage also ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mile
The mile, sometimes the international mile or statute mile to distinguish it from other miles, is a British imperial unit and United States customary unit of distance; both are based on the older English unit of length equal to 5,280 English feet, or 1,760 yards. The statute mile was standardised between the British Commonwealth and the United States by an international agreement in 1959, when it was formally redefined with respect to SI units as exactly . With qualifiers, ''mile'' is also used to describe or translate a wide range of units derived from or roughly equivalent to the Roman mile, such as the nautical mile (now exactly), the Italian mile (roughly ), and the Chinese mile (now exactly). The Romans divided their mile into 5,000 Roman feet but the greater importance of furlongs in Elizabethan-era England meant that the statute mile was made equivalent to or in 1593. This form of the mile then spread across the British Empire, some successor states of which ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Foot (unit)
The foot ( feet), standard symbol: ft, is a unit of length in the British imperial and United States customary systems of measurement. The prime symbol, , is a customarily used alternative symbol. Since the International Yard and Pound Agreement of 1959, one foot is defined as 0.3048 meters exactly. In both customary and imperial units, one foot comprises 12 inches and one yard comprises three feet. Historically the "foot" was a part of many local systems of units, including the Greek, Roman, Chinese, French, and English systems. It varied in length from country to country, from city to city, and sometimes from trade to trade. Its length was usually between 250 mm and 335 mm and was generally, but not always, subdivided into 12 inches or 16 digits. The United States is the only industrialized nation that uses the international foot and the survey foot (a customary unit of length) in preference to the meter in its commercial, engin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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