For example, if we're talking about a pitcher, like Matsuzaka, we might want to know the speed of his average fastball.
举例来说,如果我们谈到一个投手,就像松阪,我们想知道他投出,快球的平均速度。
Let's plot droplet velocity as a function of looking at the number that have this velocity 0 with the zero being in the center here.
我们将液滴的速度设定为,观察那些数字作用,在中心的地方,速度为。
So, if we're trying to figure out the wavelength of a Matsuzaka fastball, we need to consider the velocity first, which is 42 miles per hour.
如果我们尝试计算一个,松阪发出快球的波长,我们首先需要考虑速度,每小时为42英里。
Having said that, let's assume that we do have the slower tempo here, one--Let me play a little bit at the piano.
说完这些,假设我们运用较慢的速度,一,我还是在钢琴上弹一下
That means we can also measure velocity slightly later and make the slightly later come as close to right now as we want.
那我们也可以测出稍微迟一点的速度,让那个速度接近我们前面测得的速度
Insurance was invented in the 1600s but it did not proliferate fast, it proliferated only very slowly.
保险学产生于17世纪,但是它的发展速度并不快,我们甚至可以说它发展得很慢
They're very easy. And we're going to ramp up.
他们非常简单,我们会加快速度的。
In other words, replacing the shortest distance between two points that we experience in a practical message, "literariness," as the formalists call it, or "poetic language," as they also sometimes call it and as the New Critics certainly call it, slows us down.
也就是说,实用语言以最短的距离,联系两点,而文学性,如形式主义者所称,或诗意的语言,他们有时也会这么叫,新批评派成员一定会这么称呼,使我们的理解速度慢了下来。
And we turned to a discussion of the unpredictability of death, -- the fact that because we don't know-- we can't predict--how much more time we've got, we may, as it were, pace ourselves incorrectly.
我们转而讨论死亡的不可预测性,因为我们不知道-,我们不能预测--我们还有多少时间,我们可能,可以说是,为自己定错了前进的速度。
When the charge is applied, if the upper plate is negative, we would expect that the negative droplet would be repelled at a rate exceeding the gravitational fall.
当电荷起作用时,如果上边的板子是负电的,我们可以期待负电的液滴会,超过重力下降速度的速度被排斥。
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。
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。
The angle is increasing at a steady rate, so we know it's going at a steady speed.
转过的角度以恒定速率增加,所以我们知道它以一个恒定的速度运动
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。
Obviously, we would be retarding the music, ritardando or a retard at that particular point.
显然,我们也可以放慢音乐的速度,这时的术语叫做,渐慢
And since we are not expecting the mass of the particle to change, what we really are saying is the uncertainty in its velocity times the uncertainty in its position is greater than the ratio of the Planck constant divided by 2 pi.
因为我们不期望,粒子质量发生变化,我们说的是,它速度的不确定度,乘以它位置的不确定度,比普朗克常量,除以2除以圆周率要大。
We all have an intuitive notion of velocity right now.
我们现在都有一个对速度的直观概念
That limit will be some arrow we can call the velocity at the time and it will always be tangent to the curve.
那个极限也就是一个矢量,我们称之为瞬时速度,并且它总是和轨迹相切的
In particular, the things that I say are at rest, you will say are moving backwards at the velocity that you have relative to me.
特别是那些在我看来是静止的物体,在你看来却在后退,后退的速度等于我们之间的相对速度
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。
NO So that the more complete answer to the question is that no, we're never going to be able to observe that because of the uncertainty principle it's not possible to observe a velocity that's this slow for a macroscopic object.
所以这个问题的完整答案是,由于不确定性原理,我们不可能测量到这么慢的,宏观物体的速度,希望这个解释。
What de Broglie is saying we can know the wavelength of any matter at all, as long as we know its mass and it's velocity.
通过德布罗意所说的,只要我们知道了,它的质量和速度,我们可以知道,任何物质的波长。
So, first we have Matsuzaka at 94 miles per hour.
所以,首先我们知道松阪的,投球速度是94公里每小时。
That is the whole triumph of calculus is to know that by looking at the position now, the position slightly later and taking the ratio and bringing later as close as possible to right now, we define a quantity that we can say is the velocity at this instant.
这就得靠微积分了,通过了解它现在的位置,和一小段时间以后的位置,计算它们的比,再让时间间隔尽可能缩短,我们就定义了一个,被我们称之为瞬时速度的物理量
So v of t, v is the limit, and we use the symbol dx/dt for velocity.
点的速度等于一个极限,我们用符号dx/dt表示速度
Home prices are falling at the highest rate we've ever seen. I have my own index s Case-Shiller indexes the Standard & Poor's Case-Shiller indexes and we announced our indexes yesterday.
房价正在以我们从未见过的速度下跌,我有自己的一个指数,名字叫The,Standard&Poor’,而且昨天我们公布了我们的指数。
You shoot something, you should know when it will land, where it will land, with what speed it will land, how high it will go.
抛出一个物体,我们要知道落地时间,落地位置,还有落地的速度,最高点的高度
Alright. So, since we have these terms defined, we know the frequency and the wavelength, it turns out we can also think about the speed of the wave, and specifically of a light wave, and speed and is just equal to the distance that's traveled divided by the time the elapsed.
好了,我们已经定义了,这些术语,我们知道了,频率和波长,现在可以来考虑,波的速度了,特别是光波的速度,速度等于它走过的距离,除以所用的时间,因为我们。
Once you can take one derivative, you can take any number of derivatives and the derivative of the velocity is called the acceleration, and we write it as the second derivative of position.
只要你能求一阶导数,你就能求任意阶的导数,速度的导数被称为"加速度",我们把它写成位移的二阶导数
What it means is if you'd release a rock at that location one second before with a certain speed that we can calculate, it would've ended up here with precisely the position and velocity it had at the beginning of our experiment.
它的意义在于,若在该处以特定速度抛出一个物体,这个速度可通过计算得到,一秒之后,物体会运动至我们设定的起点,并且速度为我们设定的初速度
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