Mega- 19938 223126139 2008-07-02T18:09:46Z EmersonLowry 1741227 changed a square symbol to a cube symbol. {{lowercase}} {{wiktionary|mega-}} {{otheruses|Mega}} '''mega-''' (symbol '''M''') is an [[SI prefix]] in the [[SI]] system of [[Units of measurement|unit]]s denoting a factor of [[1 E6|10<sup>6</sup>]], 1,000,000 (one [[million]]). For example, 1 MW (megawatt) = 1,000,000 [[watt]]s = 1,000 [[kilowatt]]s. Confirmed in 1960, it comes from the [[Greece|Greek]] μέγας, meaning ''great''.<ref>{{OED|[http://dictionary.oed.com/cgi/entry/00304790 mega-]}}</ref> ==Other common examples of usage== * one [[megaton]] [of TNT] (a unit often used in measuring the explosive power of [[nuclear weapon]]s) is 1,000,000 tons of TNT. * [[megahertz]] — frequency of [[electromagnetic radiation]] for radio and television broadcasting, [[GSM]], etc. 1 MHz = 1,000,000 [[Hertz|Hz]]. ==Square and cubic forms== As the SI-prefixes take precedence over exponents, * 1 Mm² means one square [[megametre]] or the size of a [[Square (geometry)|square]] of 1,000,000 m &times; 1,000,000 m or <math>10^{12}</math> m² (and not 1,000,000 &times; a [[square metre]] or <math>10^{6}</math> m²) * 1 Mm³ means one cubic [[megametre]] or the size of a [[cube]] of 1,000,000 m &times; 1,000,000 m &times; 1,000,000 m or <math>10^{18}</math> m² (and not 1,000,000 &times; a [[cubic metre]] or <math>10^{6}</math> m³) ==Computing== In [[computing]], mega- can sometimes denote 1,048,576 (2<sup>20</sup>) of information units (example: a [[megabyte]], a megaword), but can denote 1,000,000 (10<sup>6</sup>) of other quantities, for example, transfer rates: 1 megabit/s = 1,000,000 [[bit/s]]. The prefix ''[[mebi]]-'' has been suggested as a prefix for 2<sup>20</sup> to avoid ambiguity, but is yet to be widely used. {{SI prefixes}} ==See also== *[[SI prefix]] *[[Binary prefix]] *[[Mebibyte]] *[[Orders of magnitude]] ==References== <references/> ==External links== *[http://www.bipm.org BIPM website] [[Category:SI prefixes]] [[br:Mega]] [[ca:Mega]] [[cs:Mega]] [[da:Mega-]] [[et:Mega-]] [[es:Mega]] [[eo:Mega]] [[fa:مگا]] [[fr:Méga]] [[hi:मेगा-]] [[ko:메가]] [[it:Mega]] [[he:תחיליות במערכת היחידות הבינלאומית#.D7.9E.D7.92.D7.94]] [[mk:Мега]] [[nl:Mega (voorvoegsel)]] [[ja:メガ]] [[no:Mega]] [[nn:Mega]] [[nds:Mega]] [[pl:Mega]] [[pt:Mega]] [[ksh:Mega]] [[ro:Mega]] [[sk:Mega]] [[sl:Mega]] [[sr:Мега]] [[fi:Mega]] [[sv:Mega]] [[vi:Mêga]]