So this is our final equation, and this is actually called the Balmer series, which was named after Balmer, and this tells us the frequency of any of the lights where we start with an electron in some higher energy level and we drop down to an n final that's equal to 2.

把2代入到这里，所以得到1除以,这就是我们最终的方程，这叫做Balmer系，以Balmer名字命名的,它告诉我们从高能级掉到n等于2的,最终能级所发出光的频率。

麻省理工公开课 - 化学原理课程节选

So it's a more specific version of the equation where we have the n final equal to 2.

当我们令n等于2时,使这个这个方程变成更具体的版本。

麻省理工公开课 - 化学原理课程节选

What is y-y0? The final y is 0, the initial y is 15. You solve for that equation and you will find the final velocity.

-y0是什么,末态的y是0,初态的y是15 你们已经得到,然后你可以找到最终速度

耶鲁公开课 - 基础物理课程节选