The key was to use a pulley system that would magnify the applied force.

关键是要使用滑轮系统，以扩大其作用力。

youdao

That is, for every force applied to an object or surface, that object pushes back with equal force.

也就是说，对于任一物体或表面施加的作用力，该物体或表面必会产生相同的反作用力。

youdao

Thus, dark matter must exist, and it was wrenched apart from normal matter by the force of the collision of the clusters.

因此，暗物质一定存在，而且星云团的碰撞产生的作用力将暗物质同普通物质相分离。

youdao

So, what we're looking at here is the force when we have two charged particles, one positive one negative -- here, the nucleus and an electron.

我们现在研究的是,一正一负俩个带电粒子之间的,作用力-在这里。

麻省理工公开课 - 化学原理课程节选

But you can also look at it qualitatively, so, if you think about the force between the electron and the proton, you could just qualitatively think about what's happening.

但你也可以定性的来研究这个问题，所以如果你们考虑电子,和质子之间的作用力,你可以定性的来想。

麻省理工公开课 - 化学原理课程节选

You can ask what the force that this quark will exert on that quark at a certain separation.

你会问,这个夸克对一段距离以外的那个夸克,有多大的作用力

耶鲁公开课 - 基础物理课程节选