纳米(nm)是长度单位.1纳米为十亿分之一m,即1nm=10^9m,一根头发的直径约0.0499mm,0.0499mm=( )nm

问题描述:

纳米(nm)是长度单位.1纳米为十亿分之一m,即1nm=10^9m,一根头发的直径约0.0499mm,0.0499mm=( )nm

4.99*10^-11��̣�0.0499mm=0.0499*10^-9nm=4.99*10^-11nm