That's how by either balancing the unknown force with a known force or by simply measuring the acceleration as I fall towards this podium and multiplying by mass, you can find the force that exerts on me.

我们既可以让未知力与已知力平衡,也可以只测量我冲向讲台时加速度的大小,再与我的质量相乘,都能求出作用在我身上的力的大小

耶鲁公开课 - 基础物理课程节选

Prof Sir Paul Newton said weapons of mass destruction could fall into the wrong hands if the state disintegrated.

BBC: Professor Sir Paul Newton

Car manufacturers have seen sales of their smaller, mass-market models fall off, with lower income buyers unable to afford new cars in the economic downturn.

BBC: European car sales in first rise for 18 months

After mass layoff announcements this fall, Society for Human Resource Management found that 23% of human-resource professionals surveyed have encountered significantly more cases of eavesdropping in the workplace over the past 12 months.

WSJ: Job Fears Make Offices All Ears