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If de Broglie is correct, we could then model the electron in its orbit not moving as a particle, but let's model it as a wave.
如果德布罗意是对的，那么我们可以在电子轨道中建立电子模型,不是像粒子一样运动，而是像波一样运动。
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You reduce a lot of the health risks, if you exercise often.
如果你经常运动的话，它会帮你降低许多健康问题的风险。
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But Aristotle used to think that if you want something to move, there has to be some agency making it move.
但亚里士多德认为,如果要让物体运动,那就必须有某种作用让它运动
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So, if instead you put your particle somewhere down here on the electric field, or on the wave, the electric field will now be in the other direction so your particle will be pushed the other way.
还有方向，所以如果,你把粒子放在这下面，电场的方向相反,粒子会朝另一个方向运动。
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So if you were learning rhetoric, for example, you might practice giving speeches at the gymnasium.
如果你在学习修辞学，就可以在运动场通过演讲来练习。
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If you decide to raise your hand, those are motor neurons telling the muscles what to do.
如果你要举手,这些运动神经元会告诉肌肉该做些什么
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For example, like it has done recently if you've been following it earlier this year.
举个例子,如果你们今年关注股票市场的话,会发现今年年初的股票运动趋势非常戏剧化
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If Frederick Jackson Turner had anything right in "The Frontier Thesis", although he didn't pay hardly any attention to the South, this idea of a safety valve of a West to move to was surely there for slavery.
如果弗雷德里克·杰克逊·特纳,在《边境论》中有什么正确的言论,那就是,尽管他对南方几乎没有施以任何关注,即这个西进运动是一道安全阀的构想,显然是为奴隶制而设的
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If you think of two towns down here, Brive,b-r-i-v-e,famous for its rugby, and Tulle,t-u-l-l-e,which is a capital.
如果你可以想起来这儿的两个城镇,布瑞福,b-r-i-v-e,以英式橄榄球运动而负有盛名,图勒,t-u-l-l-e,是一个省的首府
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if you're athletically inclined. There's an amazing gym,
如果你倾向于运动。有一个了不起的健身房，
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If a photon which has no mass can behave as a particle, does it follow then an electron which has mass can behave as a wave? 1920.
如果一个没有质量的光子,能像粒子一样运动，那么它能像一个,没有质量的电子那样以波的形式运动吗。
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So, for example, if you were trying to study the motion of some object, here is one example.
举个例子,如果你想研究某个物体的运动,这里有个例子
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It's very clear you don't need a force if something is doing nothing, just sitting there.
显而易见,如果物体没有运动,只是静止状态,那是不需要力的
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When a body is going around a circle, they say that's some centrifugal force acting.
如果一个物体做圆周运动,他们就说有离心力作用于这个物体
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One way is to just use your common sense and realize that if you push it this way, these two guys are going to move together.
第一种方法就是你可以通过常识感觉到,如果你这样推它,这两个物体会一起运动
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That means, if you are going in a plane and you throw something up in the air, it seems to be going up and down to you.
也就是说,如果你在飞机中,你向空中扔出一物体,它也许会相对于你上下运动
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That's correct. So her answer was, if it was a full parabola, then we know it would've been at the ground before I set my clock to 0.
她说,如果运动轨迹为一条完整的抛物线,那么它在我们所设定的零时刻之前,就已经落地了
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If you want to describe this particle, what's the kinematics?
如果你想描述这个质点,如何从运动学角度来描述呢
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For example, if you started here and you did all this and you came back here, the average velocity would be zero, because you start and end at the same value of x, you get something; 0 divided by time will still be 0.
例如,如果你从这里开始运动,经过这个过程又回到这里,平均速度就是0,因为初态和末态的位移相同,你得到了什么呢,0除以时间还是0
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Now, what happens if the elevator is accelerating upwards with an acceleration a?
现在如果电梯向上以加速度 a 运动,会发生什么呢
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I know that if the second mass moved faster than the first one, then the picture is completely wrong.
因为我知道如果第二个物体比第一个运动更快,那么受力图就肯定不是这样了
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So, if we do this calculation for an electron, saying it moves at 10 to the 5 meters per second, then what we end up with for a wavelength is 7 times 10 to the -9 meters.
如果我们已知电子以，10的5次方每秒的速度运动，那么做一个计算,可以得知它的波长是,7乘以10的负9次方米。
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So the Earth is an inertial frame of reference, if you go in a train relative to the Earth at constant velocity, you're also inertial.
所以,地球是一个惯性参考系,如果你坐在相对于地球匀速运动的火车里,你也处于惯性状态
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What that means is, if you know the velocity of the given time and you know the initial velocity, you know what time it is.
这个方程的意义是,如果你知道某个给定时刻的速度,并且知道初速度,你就能知道运动的时间
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They'll keep trying to get it going, but maybe we should move on with our lives here while this is happening, and we'll click it back at the end, and if we have a nice set up at any point, I'll just stop and we'll go back and we'll look at it again.
它们会一直让它保持运动，但是或许我们应该,在这个过程中离开一会儿，我们在最后点击它，如果我们在每一个点,都有一个好的装置，我就会停止然后,返回再去看看它。
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Somehow, if you could manufacture a really smooth frictionless surface, that if you took a hockey puck or something and an air cushion and you give it a push, in some idealized world, it'll travel forever.
如果你制造一个绝对光滑无摩擦的表面,然后在上面放个冰球或者别的什么,或者气垫,然后推它一下,在理想条件下,它会永远运动下去
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But if I'm accelerating, the force exerted by the spring and therefore, the needle the weighing machine reads is m.
但是如果我在加速运动,那么弹簧的弹力,也就是称重机上指针的读数就是 m
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If it's going in a circle, you will say from now on, that it, indeed, has an acceleration, even though no one's stepping on the accelerator, of amount v^2 over R.
如果它在一个圆周上运动,你会说从现在起它其实有加速度,即使没有人去踩油门,加速度大小为 v^2 / R
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If I am an inertial observer, another person moving relative to me at constant velocity will also be an inertial observer.
如果我是惯性观察者,那另一个相对于我做匀速运动的人,也是一个惯性观察者
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