If you put your fingers between the crevice at the bottom, and here's where you gotta watch out for the spring, pull the thing apart and that's it.

如果你把手指放到底部的缝隙中间，这里你需要小心弹簧，把东西分开，就是这样。

youdao

Now I replace this object by mass m2 but the extension is the same, so the pull must be same the spring doesn't know what the mass is at the other end, right?

再以质量m2的物体做同一个实验2，弹簧伸长相同，可知拉力相同，这与悬挂物体的质量，无关？

youdao

And if you have a pull down here and you have a pull up here and you have in here a spring then you see you have a way of measuring that force.

往下拉这儿的话,会产生向上的拉力,中间有根弹簧,它能帮助你测出力的大小了。

youdao

If you put your fingers between the plastic opening at the bottom, and here's where you gotta watch out for the spring, pull the thing apart and that's it.

如果你把手指放到,底部的缝隙中间，这里你需要小心，你剥开就会发现这个了。

哈佛公开课 - 计算机科学课程节选

Even in the case of this spring, when you pull it, if you pull it to the right by some force.

甚至是在这样的弹簧问题中,当你拉它的时候,如果你用力向右拉

耶鲁公开课 - 基础物理课程节选

I draw a graph here of the amount by which I pull the spring versus the force it exerts.

我在这里画个图,纵轴是弹簧的拉伸量,横轴是力的大小

耶鲁公开课 - 基础物理课程节选

That push-pull of supply vs. demand will keep prices elevated as we head into the spring selling season and its looking like that shopping season will be weaker this year than last.

FORBES: Uh-Oh, Even Wal-Mart Faces The Cash Strapped Consumer