Researchers from the African Soil Information Service will study earth samples and rate them.

VOA: special.2009.01.20

So, when you divide by m, m cancels and everything falls at the same rate on the surface of the Earth.

因此,当等号两边除以 m 时,m 被消去了,在地球表面的所有物体,都以相同的加速度下落

耶鲁公开课 - 基础物理课程节选