To find the force, what you will do is, suppose somebody says, "Hey, I've got a new force.

为了找出这些力,你们要做的是,假设有人说,"嘿,我发现了一种力

耶鲁公开课 - 基础物理课程节选

And then watch what happens to the prose style and the difference in tone: I find it most difficult to express with adequate force that flash, that shiver, that impact of passionate recognition.

然后看看那些散文风格,及语调发生的改变：,我发现要恰如其份地表现一刹那的那种颤栗，那种动了感情发现的碰撞，真是最为困难。

耶鲁公开课 - 1945年后的美国小说课程节选

Then you find that you have to apply minimum force.

你就会发现,所需外力有最小值

耶鲁公开课 - 基础物理课程节选

Here's another force you might find.

你可能会发现还有一种力

耶鲁公开课 - 基础物理课程节选

It looks like a tautology because you're never able to show me something that moves forever at a constant velocity, because every time you don't find such a thing, I give an excuse, namely, a force is acting.

这听上去像个死循环,因为你不可能,找到永远匀速运动下去的物体,因为每当你找不到这样的物体时,我就会给出一个理由,也就是,有力作用在上面

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