There'll be an equal and opposite reaction in the violent extremist community.

VOA: standard.2009.10.16

So, massless bodies will always have, like a massless rope, equal and opposite forces on the two ends.

所以无质量的物体,比如这个绳子,两边所受的力永远都相等

耶鲁公开课 - 基础物理课程节选

you're looking for that equal and opposite forces acting at two ends of the rope.

你就得求出作用在绳子两端的,大小相等方向相反的力

耶鲁公开课 - 基础物理课程节选

Right. I don't want to give it too many different names, because F2, 3 and F3, 2 are equal and opposite.

没错,我不想用太多不同的名字,因为 F23 和 F32 大小相同方向相反

耶鲁公开课 - 基础物理课程节选