字幕列表 影片播放 列印英文字幕 Mega is a unit prefix in the metric system denoting a factor of one million. It was confirmed for use in the International System of Units in 1960. Mega comes from the Greek μέγας megas, meaning "great". Other common examples of usage megapixel - 1 million pixels in a digital camera one megatonne is the approximate energy released on igniting one million tonnes of TNT. megahertz — frequency of electromagnetic radiation for radio and television broadcasting, GSM, etc. 1 MHz = 1,000,000 Hz. Exponentiation When units occur in exponentiation, such as in square and cubic forms, any size prefix is considered part of the unit, and thus included in the exponentiation. 1 Mm2 means one square megametre or the size of a square of 1000000m by 1000000m or 1012m2, and not 1000000square metres. 1 Mm3 means one cubic megametre or the size of a cube of 1000000m by 1000000m by 1000000m or 1018 m3, and not 1000000cubic metres Computing In computing, mega may sometimes denote 1,048,576 of information units, but denotes 1000000 units of other quantities, for example, transfer rates: 1megabit/s = 1000000bit/s. The prefix mebi has been suggested as a prefix for 220 to avoid ambiguity. See also Binary prefix Mebibyte Metric prefix Order of magnitude References External links BIPM website