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And then we have c, the speed of light, 2.998 times 10 to the 8 meters per second.
然后我们知道光速等于，2，998乘以10的8次方米每秒。
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That means our energy is equal to 6.626 times 10 to the -34 joules times seconds.
这意味着能量等于,6，626乘以10的-34次方焦耳每秒。
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One way to mark time is to imagine it carries a clock as it moves, and put markers every second.
标记时间的一种方法是,想像它带着时钟运动,并且每秒做一次标记
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And then I could put a couple of plates and I could raster the beam so that when I am looking here,the beam goes back and forth about 80 times a second.
然后我放了两个感光片,我可以检测到光束所以,当我观察时,电子束以每秒80次的速度来来回回了。
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How do you know something like this doesn't happen every single night, every hour on the hour, ? every minute, every second?
你怎么知道这样的事,每一晚，每个小时，每分每秒都没有发生？
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So, if something cycles through five wavelengths in a single second, we would just say that the frequency of that wave is five per second.
如果一个东西在一秒,内经历了五个波长，我们就说这个波的,频率是每秒5次。
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So, if we kind of think about the numbers we would need, we would actually need a velocity that approached something that's about 10 to the negative 30 meters per second.
所以如果我们稍微想想，我们需要的数值是多少，我们需要一个,大约为10的负30次方米每秒的速度。
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So, keep in mind that one milliwatt is just the same as saying 1 times 10 to the -3 joules per second.
所以，请记住1毫瓦,和1乘以10的-3次方焦耳每秒,的说法是等同的。
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You get 2.18 times 10 to the plus 6 meters per second, 1% which is about 1% of the value of the speed of light.
。18*10^6米每秒，得到的速度大概是光速的。
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If the units come out in meters per second, you will quickly discover that the problems in 3.091 are just not that complicated.
如果你的单位是米每秒，你会很快发现,在3。091中的题目并不复杂。
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So, we would actually need a really, really, really tiny velocity here to actually overcome the size of the mass, if we're talking about macroscopic particles, to have a wavelength that's going to be on the order.
是10的负34次方焦耳每秒,所以如果我们谈论的是要一个，宏观粒子有相应数量级的波长的话，我们需要一个非常非常非常小的速度来。
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The one thing you want to keep in mind though is that Hertz does not actually mean inverse seconds, it means cycles per second. So, if you're talking about a car going so many meters per second, you can't say it's going meter Hertz, you have to say meters per second.
写成5每秒，或5赫兹,你们要记住的是赫兹,并不等于秒的倒数，它是每秒的循环数，如果你们说,一辆车一秒可以走多少米,你不能说它走了米赫兹。
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So, this really just means for frequency, it's a frequency label.
你要说米每秒，所以它仅仅是，用来表示频率的，是个频率的标志。
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So, the way to measure force is in kilogram meters per second squared.
所以,力的单位是千克米每秒平方
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If the units are supposed to come out in meters per second and you get seconds per meter, what do you figure the chances of that problem being right are?
因为如果单位本应该是米每秒,但你写的是秒每米，你认为这个题目,还有正确的机会吗？
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We divide that by the mass, so 0.12 kilograms, that's the mass of a regulation baseball for the major leagues, and the velocity of the baseball is 42 meters per second. So, we can cross out our units doing our unit analysis.
我们用质量来除它，质量为0，12千克，这是大多数联赛规定的棒球质量,棒球的速度为42米每秒,所以，我们可以消去单位,来做单位分析。
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Acceleration is measured in meters per second squared.
加速度的单位是米每秒平方
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If your plan is to accelerate a 3 kg mass with an acceleration of 2 meters per second, you better have a rope that can furnish that force and it can take the tension of 6 Newtons.
如果你想用 2 米每秒平方的加速度,去拉一个 3 千克的物体,那么你就需要一根能提供拉力的绳子,并且它能够承受 6 牛的张力
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You see an object in motion, you find a and you give a a certain numerical value, 10 meters per second squared.
你看到一个物体在运动,你会发现它的 a,然后给 a 赋值,10 米每秒平方
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Frequencies, how many times you go around, f is revolutions per second It's called the angle of velocity.
频率就是一秒转多少圈,因为 f 是每秒转过的圈数,这就是角速度
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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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0 Hertz means you do 60 revolutions per second.
0Hz 的意义是每秒经过60个周期
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So, we can just plug it in. Speed is equal to the distance traveled, which is lambda over the time elapsed, which is 1 over nu. so, we can re-write that as speed is equal to lambda nu times nu, and it turns out typically this is reported in meters per second or nanometers per second.
经过的距离和所花的时间,我们把它们带进来,速度等于经过的距离,也即是lambda除以,所花的时间,通常它的单位,是米每秒或者纳米每秒。
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