Plus the potential energy, which is mg times R times one minus cosine theta.
加上势能，也就是mg乘以R乘以,1/cosθ
So you're using, then, the conversion of gravitational potential energy to kinetic energy.
所以你在利用，重力势能，转换成，动能。
Now we forced this potential energy... we forced it into being dependent on theta squared.
现在我们使得势能。,我们强迫它,随着θ的平方而变。
So the kinetic energy has increased; the potential energy is the same, so the total energy is up.
所以动能增加，势能不变，所以总能量增加。
This is the kinetic energy for something in orbit at this radius, and this is the potential energy.
这是在轨道内这个，半径的物体的动能，这是势能。
Then we have the conservation - of mechanical energy — the sum of kinetic energy and potential energy.
我们知道，机械能守恒定律-，动能和，势能的总和。
At infinity, there's no stored potential energy, and it drops off more and more negative as one over r.
在无限远处，没有储存的势能，并且它向负方向减少，当距离超过R时。
And I accidentally mentioned that it 0 was the potential energy that is zero, which is obviously not so.
我无意间提起,这里的势能为，但是很明显并不是。
And so I put potential energy in the spring by pushing them together, and they are lined up now here.
弹簧中储存了能量，把它们挤在一起，它们排列在这里。
So if I make a plot of the gravitational potential energy as a function of y, then I would get a straight line.
因此如果我画一张,重力势能,受y变化的图，那么会得到一条直线。
When I'm here, gravitational potential energy ; increases in this way; the gravitational force is in this direction.
重力势能，这样增长,重力;,是在这个方向,当我在这里。
The change in potential energy is going to be the change in kinetic energy You have conservation of energy principles.
势能的改变量，将会转化成动能的改变量，这就是能量守恒定律。
We have defined potential energy 0 to be zero at infinity, and that is why all bound orbits have negative total energy.
我们规定，无限大时,势能为，这就是为什么所有的,规则轨道总能量为负。
So what, now, is then the total -- energy of the system-- that is, the sum of the kinetic energy plus the potential energy?
所以现在系统内,总能量是多少-,是动能和,势能之和吗？
Remember that depending upon how you define your zero level here, you also end up with negative values for potential energy.
记住这个值取决于，你怎么定义0水平，你的得到的势能，也是负值。
I could have chosen it right here and nothing would change other than that I offset the zero point B of my potential energy.
除了会抵消零点，势能什么的，都不会变，但是如果我从A到。
You see there first the component of the kinetic energy, which is the and then you see the term which is the potential energy.
你在这里看到的是,动能的公式,这一项,是势能。
I can never predict The Times, because if I make the spring more squeezed, then obviously I will have more potential energy.
我无法预测时间，因为弹簧压缩得更紧，这样就储存更多能量。
You can install a disk in your car, which I would call, then, a flywheel, And you can convert the gravitational potential energy.
可以在车内装个圆盘，可以称之为飞轮，可以转化，重力势能。
And, in fact, it can't even reach n, because then we would have no potential energy at all in our electron, which is not correct.
事实上，它连n都达不到，因为如果那样的话，电子就没有势能了，这是不可能的。
Then this will have a positive gravitational potential energy, and this will have one that is higher than this one by this amount.
那么它将是,正的重力势能，这样的话这点,就比另一点高。
Now, what we would like to do is we would like to convert all this gravitational potential energy into kinetic energy of that disk.
现在要做的，就是要转化，所有这些重力势能，变成圆盘的动能。
The limitations are that you just can’t charge the batteries fast enough to take all the potential energy that’s available in a braking event.
那些限制就是，在一次刹车期间，你只是无法给蓄电池充电充的足够快而取走所有潜在的可以利用的能量。
The limitations are that you just can't charge the batteries fast enough to take all the potential energy that's available in a braking event.
那些限制就是，在一次刹车期间，你只是无法给蓄电池充电充的足够快而取走所有潜在的可以利用的能量。
Even Fortune 500 companies that have long employed lobbyists on other issues have needed to hire more to track potential energy policy changes.
甚至是一直雇佣说客对其他事情进行游说的财富500强公司也需要雇佣更多的人来追踪在能源政策可能发生的可能的变化。
C at this point c, this has reached a maximum velocity that it can ever have because all the potential energy has been converted to kinetic energy.
在这个点，达到它能达到的，最大动能，因为所有的势能，都转化成了动能。
There is a conversion from gravitational potential energy to kinetic energy back to gravitational potential energy, and it will come to a stop here.
这就是重力势能，转换到，动能，再回到，重力势能，最终停在这里。
If we know the force — in this case, the spring force or in those cases, - the gravitational force — we were able to calculate the potential energy.
在这个例子里-，弹力，或这些例子里，重力，我们能够-，计算出势能，现在问题是。
It means that we better get away from these deterministic models where we have a little electron here with its potential energy and its kinetic energy.
它的意思是我们最好远离，这些确定性模型，那里有一个小电子，它具有势能和动能。
Kinetic energy can be converted back to potential energy, can be converted back, - but the sum of them — which we call "mechanical energy" — is conserved.
动能可以转化，成为势能，也可以转化为动能，但是总和-，我们叫做的，机械能，是恒定的。
应用推荐