Chapter 1 Introduction Consistent set of units Base quantities基本量: length,time,mass Base units(基本单位): meter; second, kilogram Derivative quantities(导出量):The quantities derived from base quantities such as: velocity, acceleration Derivative units(导出单位): The units derived from base units such as: m/s m/sChapter 1 Introduction Base quantities(基本量): length, time, mass. Base units(基本单位): meter, second, kilogram. Derivative quantities( 导 出 量 ): The quantities derived from base quantities such as：velocity， acceleration . Derivative units( 导 出 单 位 ): The units derived from base units such as：m/s m/s2 . Consistent set of units