用第三人称写(“含水层涵盖1000平方公里”)，或第一人称复数(“从这个等式我们看到，加速度与力成正比”)。

Write in the third person (" the aquifer covers 1000 square kilometers ") or the first person plural (" We see from this equation that acceleration is proportional to force ").

youdao

地球也会坠向苹果-，因此地球上的力与地球的质量相等，再乘以地球的加速度。

Well, the earth is going to fall towards the apple — So the force on the earth is the mass of the earth times the acceleration of the earth.

youdao

这一也十分重要-，加速度与力方向相同。

That's also important — the acceleration is in the direction of the force.

youdao

But the acceleration it produces on the elephant and on the mass, are in an inverse ratio of their masses.

但这个力使大象和物体产生的加速度,与它们的质量成反比

耶鲁公开课 - 基础物理课程节选

Therefore, when you divide by the mass to get the acceleration, the response of different bodies is inverse to the mass.

因此,当你拿力除以质量得到加速度时,不同物体的加速度与质量成反比

耶鲁公开课 - 基础物理课程节选

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