The second piece of information we need to know is what actually the kinetic energy is of the ejected electron, and that's something we can just measure by measuring its velocity.

其次，我们需要知道的信息是,出射电子的动能，这可以通过,测量它们的速度得到。

麻省理工公开课 - 化学原理课程节选

And, that's a good thing to know because if you come out with an answer that's somewhere near the diameter of the universe and it's supposed to be the diameter of an atom, then you will know that you probably made a mistake.

这是我们需要知道的,因为当你做一道题得到的答案,是宇宙的直径,而正确答案是原子直径时，你能很快发现你的错误。

麻省理工公开课 - 固态化学导论课程节选

Now remember, we went through before how it's a state function but to calculate it, you'd need to find a reversible path, along which you can figure this out.

请记住，我们不需要知道它是怎样的一个态函数,只计算就可以了，你需要找到一条可逆路径，沿着这条路径就能算得这个结果。

麻省理工公开课 - 热力学与动力学课程节选

Remember, we're talking about angular nodes here, so you need to read the question carefully.

要知道，我们这里讨论的是角向节点，大家需要看清题目问的是什么。

麻省理工公开课 - 化学原理课程节选

Knowing what iambic pentameter is, is not a gift of birth, but rather something that comes through a little bit of practice, which means we have to work at it a little bit.

没有谁是生来就知道抑扬五音步格诗，是需要努力才能知道的，这说明我们必须在这个上面花点功夫。

耶鲁公开课 - 现代诗歌课程节选

And that we need to see your work to get full credit, and then especially if you get things wrong, we need to know where it went wrong.

我们需要看到这些才能给你所有分数，尤其是当你出错的时候，我们需要知道是哪里错了。

麻省理工公开课 - 化学原理课程节选

Once we can do that we can go on and say okay, what actually is a wave function, but first we need to know how to describe which ones were talking about.

我们就可以继续并说波函数到底是什么,但首先，我们需要知道，如何描述,我们说的,是哪一个波函数。

麻省理工公开课 - 化学原理课程节选

Yeah, good. So, they're actually helium atoms, helium ions. And this wasn't really important for the studies, it didn't matter that didn't know what they are but it's nice to kind of know now - that we do know what they were using.

氦粒子，这对他们的研究并不重要,他们并不需要知道它是什么,但我们最好知道,他们当时用的是什么。

麻省理工公开课 - 化学原理课程节选

We know we need to divide by 266, 266 but what we need you to help us with is to figure out this top number here and see how many particles are going to backscatter. So if the TAs can come up and quickly hand out 1 particle to everyone.

知道背散射的概率就可以了，我们知道要除以,但还需要你们来搞清楚,分子上的数是多少，有多少个发生背散射的粒子,助教们请过来,把这些球分给同学们。

麻省理工公开课 - 化学原理课程节选

We want to have that definition clear because in fact we're going to, we might want tabulate heats of reaction, right, and of course want to know what the conditions are for the tabulated values apply. And we're going to want to calculate them from other quantities and again, we're going to need to know each case what are the relevant conditions?

我们想要明确这个定义,因为实际上我们会想把,反应热制成表格，当然我们会,想知道表中的数据在什么样的,条件下是有效的，我们会,想要从其他的量中算出它们,再一次，我们需要知道,每种情形下相关的条件是什么？

麻省理工公开课 - 热力学与动力学课程节选