Deca-
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Deca- or deka-[1] (symbol da) is a decimal unit prefix in the metric system, denoting a factor of ten. The term is derived from the Greek deka (δέκα), meaning "ten".
The prefix was a part of the original metric system in 1795. It is not in very common usage, although the decapascal is occasionally used by audiologists. The decanewton is also encountered occasionally, probably because it is an SI approximation of the kilogram-force. Its use is more common in Central Europe. In German, Polish (deka, deko), Czech, Slovak and Hungarian, deca is common (and used a word on its own always means decagram). A runway number typically indicates its heading in decadegrees.
Before the symbol as an SI prefix was standardized as "da" with the introduction of the International System of Units in 1960, various other symbols were more common, such as "dk" (e.g. in the UK and Austria), "D" (e.g. in Germany), and "Da". For syntactical reasons, the HP 48, 49, 50 series as well as the HP 39gII and Prime calculators use the unit prefix "D".[2][3][4]
Examples:
- The blue whale is approximately 30 meters or 3 decameters in length.[5]
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- ↑ The metric system was introduced in 1795 with several metric prefixes, of which, however, only six were adopted as SI prefixes by the 11th CGPM conference in 1960, whereas myria (104) as well as double and demi were not adopted. In 1873, micro and mega were recommended by the British Association for the Advancement of Science. The other dates relate to recognition by a resolution of the CGPM.
See also
References
- ↑ Guide for the Use of the International System of Units (SI), 1995, NIST Special Publication 811
- ↑ HP 48G Series – User's Guide (UG) (8 ed.). Hewlett-Packard. December 1994 [1993]. HP 00048-90126, (00048-90104). Retrieved 2015-09-06.
- ↑ HP 50g graphing calculator user's guide (UG) (1 ed.). Hewlett-Packard. 2006-04-01. HP F2229AA-90006. Retrieved 2015-10-10.
- ↑ HP Prime Graphing Calculator User Guide (UG) (PDF) (1 ed.). Hewlett-Packard Development Company, L.P. October 2014. HP 788996-001. Retrieved 2015-10-13.
- ↑ http://channel.nationalgeographic.com/channel/content/kingdom-of-the-blue-whale-3302/blue-whale-facts/#/compare/length
External links
Look up deca- in Wiktionary, the free dictionary. |