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Golden ratio. A golden rectangle with long side a + b and short side a can be divided into two pieces: a similar golden rectangle (shaded red, right) with long side a and short side b and a square (shaded blue, left) with sides of length a. This illustrates the relationship a + b a = a b = φ.
Edinburgh is the capital city of Scotland and one of its 32 council areas. Located in the south-east of Scotland, it is bounded to the north by the Firth of Forth estuary and to the south by the Pentland Hills. With a population of 506,520 in mid-2020, Edinburgh is the second-largest city in Scotland by population and the seventh-largest in the ...
ISO 3166-1 – Codes for the representation of names of countries and their subdivisions – Part 1: Country codes [2] defines codes for the names of countries, dependent territories, and special areas of geographical interest. It defines three sets of country codes :
- List of Si Prefixes
- Usage
- Application to Units of Measurement
- Non-Standard Prefixes
- Similar Symbols and Abbreviations
- External Links
The BIPM specifies twenty-four prefixes for the International System of Units (SI). The first uses of prefixes in SI date back to the definition of kilogram after the French Revolution at the end of the 18th century. Several more prefixes came into use, and were recognised by the 1947 IUPAC 14th International Conference of Chemistrybefore being off...
Examples
1. The mass of an electron is about 1 rg (rontogram).[a] 2. The mass of 1 litre of wateris about 1 kg (kilogram). 3. The mass of the Earthis about 6 Rg (ronnagrams). 4. The mass of Jupiteris about 2 Qg (quettagrams).
Examples of powers of units with metric prefixes
1. 1 km2 means one square kilometre, or the area of a square of 1000 m by 1000 m. In other words, an area of 1000000 square metres and not 1000 square metres. 2. 2 Mm3 means two cubic megametres, or the volume of two cubes of 1000000 m by 1000000 m by 1000000 m, i.e. 2×1018 m3, and not 2000000 cubic metres (2×106 m3).
Examples with prefixes and powers
1. 5 mV × 5 mA = 5×10−3 V × 5×10−3 A = 25×10−6 V⋅A = 25 μW. 2. 5.00 mV + 10 μV = 5.00 mV + 0.01 mV = 5.01 mV. 3. 5 cm = 5×10−2 m = 5 × 0.01 m= 0.05 m. 4. 9 km2 = 9 × (103 m)2 = 9 × (103)2 × m2 = 9×106 m2 = 9 × 1000000 m2 = 9000000 m2. 5. 3 MW = 3×106 W = 3 × 1000000 W = 3000000 W.
The use of prefixes can be traced back to the introduction of the metric system in the 1790s, long before the 1960 introduction of the SI.[citation needed]The prefixes, including those introduced after 1960, are used with any metric unit, whether officially included in the SI or not (e.g., millidyne and milligauss). Metric prefixes may also be used...
Obsolete metric prefixes
Some of the prefixes formerly used in the metric system have fallen into disuse and were not adopted into the SI. The decimal prefix for ten thousand, myria- (sometimes spelt myrio-), and the early binary prefixes double- (2×) and demi- (1/2×) were parts of the original metric system adopted by France in 1795,[c]but were not retained when the SI prefixes were internationally adopted by the 11th CGPM conferencein 1960. Other metric prefixes used historically include hebdo- (107) and micri- (10...
Double prefixes
Double prefixes have been used in the past, such as micromillimetres or millimicrons (now nanometres), micromicrofarads (μμF; now picofarads, pF), kilomegatonnes (now gigatonnes), hectokilometres (now 100 kilometres) and the derived adjective hectokilometric (typically used for qualifying the fuel consumption measures).These are not compatible with the SI. Other obsolete double prefixes included "decimilli-" (10−4), which was contracted to "dimi-"and standardised in France up to 1961. There a...
In written English, the symbol K is often used informally to indicate a multiple of thousand in many contexts. For example, one may talk of a 40K salary (40000), or call the Year 2000 problem the Y2K problem. In these cases, an uppercase K is often used with an implied unit (although it could then be confused with the symbol for the kelvin temperat...
US NIST Definitions of the SI units: The twenty SI prefixesUS NIST Definitions of the SI units: The binary prefixesAmerican retail corporation Walmart has been the world's largest company by revenue since 2014. [1] The list is limited to the largest 50 companies, all of which have annual revenues exceeding US$130 billion. This list is incomplete, as not all companies disclose their information to the media and/or general public. [3]
Julie Frost, winner of the 2010 contest for Germany. Stefan Örn, winner of the 2011 contest for Azerbaijan. Thomas G:son, winner of the 2012 and 2023 contests for Sweden. Thomas Stengaard (left), Julia Fabrin Jakobsen (centre) and Lise Cabble (right), winner of the 2013 contest for Denmark.
The UEFA Champions League (previously known as the European Cup, abbreviated as UCL, or sometimes, UEFA CL) is an annual club association football competition organised by the Union of European Football Associations (UEFA) and contested by top-division European clubs, deciding the competition winners through a round robin group stage to qualify ...
