That is,this kind of pull-yourself-up-by-your-bootstraps, that with enough determination and hard work that you can transcend limitations of money or class or gender.

VOA: special.2010.03.08

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

The United States currently has about 130,000 troops in Iraq, and all are scheduled to pull out by 2011.

VOA: standard.2009.07.29

If you go to the web just type in glycemic index, you can pull up chart after chart of high and low glycemic index foods, and sometimes you get surprised by what those foods are.

如果你在网上输入血糖指数,你会得到一个又一个,关于食物血糖指数高低的图表,有时你会被列表中的那些食物吓一跳

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选

He stressed the threat posed by militants in the region is too great for the United States to pull out.

VOA: standard.2009.08.23

One of the first steps in that healing is that fibroblasts like this cell crawl into the space that's created by the wound and they grab a hold of both sides of the wound and contract and try to pull it together.

愈合的第一步是,成纤维细胞向,损伤的创口爬行,紧紧地抓住创口的两侧,通过收缩回拉 试着使创口合拢

耶鲁公开课 - 生物医学工程探索课程节选

Fifty-two percent of those recently polled by the Independent newspaper support an immediate pull-out of British troops from Afghanistan.

VOA: standard.2009.08.02

p So to jump from the 2 s to the 2 p, takes more energy than we can actually compensate with by increasing the pull from the nucleus.

也就是，从，2，s，跃迁到，消耗的能量超过了,由于原子核的引力增强而补偿的能量。

麻省理工公开课 - 化学原理课程节选

A majority would like to see all British forces withdrawn by the end of the year while 42 percent favor an immediate pull-out.

VOA: standard.2009.07.13

Then, I pull it again by the same amount and let it go; I do it 10 times.

然后,我再用相同的力拉它,再放手,这样做 10 次

耶鲁公开课 - 基础物理课程节选

Now I can measure that, because I pull it by one centimeter and I find the acceleration it exerts on a known mass.

现在就能测量这个力了,因为把弹簧拉伸 1 厘米,我就知道它让一个质量已知的物体产生的加速度

耶鲁公开课 - 基础物理课程节选

Namely, if you pull it by so much, that's the force it will exert.

也就是,将弹簧拉伸这么长,它产生的力就有这么大

耶鲁公开课 - 基础物理课程节选

We want to know how much force it exerts when I pull it by a certain amount.

我们想知道当我们将弹簧拉伸一定量时,它能产生多大的力

耶鲁公开课 - 基础物理课程节选

Then, I bring the elephant and I pull the spring by the same amount and I find the acceleration of the elephant and the denominator is obviously the mass of the elephant.

然后我再找来大象,用相同的力去拉弹簧,大象就具有了加速度,很明显,分母就是大象的质量

耶鲁公开课 - 基础物理课程节选

You hook one end of the spring to a wall and you pull it from rest by some amount and you attach the one kilogram mass to it.

你把弹簧的一端固定在墙上,然后拉伸一段距离,接着你把 1 千克物体固定在上面

耶鲁公开课 - 基础物理课程节选

Then I pull it by 1.1 cm, and I find ma.

然后我把弹簧拉伸 1.1 厘米,得到 ma

耶鲁公开课 - 基础物理课程节选