一、基本单位、导出单位和单位制在工农业生产和科学技术等领域中,物理量是很多的,但绝大多数物理量之间都有一定的联系,所以只要恰当地选定为数不多的几个物理量的单位,我们就有可能利用这些单位推导出其他物理量的单位来. 这些被任意选定的、相互独立的如长度、质量、时间等等物理量,叫基本量.它们的单位如米、千克、秒等等,叫基本单位;用这些基本量推 I. Basic Units, Export Units and Units In the field of industrial and agricultural production and science and technology, the physical quantities are a lot, but most of the physical quantities have a certain connection, so long as the proper selection is made for a few It is possible to use these units to derive units of other physical quantities, which are arbitrarily chosen and independent of physical quantities such as length, mass, time, etc., which are called basic quantities, and their units, such as meters, Kg, seconds, etc., called the basic unit; use these basic quantities