英和和英

出典:『Wikipedia』 (2011/08/05 12:18 UTC 版)

英語による解説

引用

The tonne (unit symbol t) or metric ton (U.S.), often written as metric tonne, is a unit of mass equal to 1,000 kg (2,204.62 lb) (10³ kilograms) which is almost exactly the mass of one cubic metre of water at four degrees Celsius. It is sometimes abbreviated to mt in the United States, although this conflicts with other SI symbols. The tonne is not a unit in the International System of Units (SI), but is accepted for use with the SI. In SI units and prefixes, the tonne is a megagram (Mg). The spelling tonne pre-dates the introduction of the SI in 1960; it has been used with this meaning in France since 1842 (when there were no metric prefixes for multiples of 10⁶ and above), and is now used as the standard spelling for the metric mass measurement in most English-speaking countries. In the United States, the unit was originally referred to using the French words millier or tonneau, but these terms are now obsolete. The Imperial and US customary units comparable to the tonne are both spelled ton in English, though they differ in mass. Pronunciation of tonne (the word used in the United Kingdom) and ton is usually identical.