- Part of the challenge is speed, too, how quickly you can get these answers in terms of getting them in on time.
部分困难也会来自于速度,你多快能做出答案,能否在规定的时间做完。
because you need to know like, how fast the shutter speed and all that stuff,
因为你必须知道,像快门的速度,还有其他这一类东西,
Perhaps the data rate was a little bit faster than you were accustomed to, but you had some familiarity.
可能这个数据速度,相比你所熟悉的有些快,但是你有一些亲切感。
He said, first, let it go a little distance, take the distance over time, that gives you the velocity now.
他说,首先,让它运动一小段距离,距离除以时间,你就能得到现在的速度
It's not always how fast you throw the fastball, sometimes it's your different styles or the different ways that you decide when to throw what.
这不总是你投出,棒球的速度有多快,有时这是你投球的类型,或者你决定采用的投球方式。
Suppose you're the driver of a trolley car, and your trolley car is hurtling down the track at 60 miles an hour.
假设你是一名电车司机,你的电车以60英里/小时的速度,在轨道上飞驰。
You have to imagine they're moving along quicker than you would by walking, so that they will go bang and we can see what happens.
你得想象他们往前跑动的速度,肯定要比你步行快,所以就像这样"砰"地撞在一起,然后大开杀戒
And you can vary the width and the speed and the length.
你能改变它们的广度,速度和长度
You have to form some kind of balance in your life and not let anyone demand a hundred hours a week of your time If they do, you should sell the stock they give as soon as you can and diversify.
你必须形成一个平衡在你的生命中,不能使任何人让你,一周工作一百个小时,如果他们这么要求了,你应该以最快的速度,把他们给你的股票卖掉然后转业。
And if you are looking at a keyboard, we can predict in the real time very rapidly that beat your very single finger typing speed, exactly the letters you like to type and hit, therefore provide a communication mechanism that Christopher Reeve and those similar with him can benefit from.
如果你在看电脑键盘,你可以十分快速地,实时预知自己手指敲击键盘的速度,预知你想录入的字母,这样便为克里斯托弗·里夫,和其他你说熟悉的人提供了一种沟通机制,使他们从中受益。
But they're being flashed so fast you don't see anything-- words like "corpse," "dead," "dying."
它们闪现的速度非常之快,你根本看不到这些词语,it,looks,like,that—,比如,尸体,死亡,垂死“
When you're driving in your car, there's a needle and the needle says 60; that's your velocity at this instant.
当你在开车时,有一根指针指着60,表示你这个时刻的速度
Things that I say are going at 50 miles per hour you may say are going at 80.
在我看来速度为每小时 50 英里的物体,在你看来速度可能是每小时 80 英里
If you took a 15 inch artillery shell moving at the velocity it typically goes at, and take that amount of kinetic energy versus the resistive capacity of a sheet of tissue paper, that's the scale that we're looking at here.
如果你有1个15英寸的炮弹,按照经典的速度移动,会消耗大量的动能,抵抗来自于一张薄纸的阻力,这就是我们在这儿看到的尺度。
c We know it's very specific for light because in this equation is c, the speed of light. So any time you go to use this equation, if you're trying to use it for an electron, just ask yourself first, does an electron travel at the speed of light?
我们知道它只对光适用是因为在这个方程里有,光速,所以下次你们用这个方程前,如果你们要把它用到一个电子上,先问问你自己,电子的运动速度是光速吗?
So technically, if you ask what does the velocity stand for-- Let me draw a general situation.
从学术角度来说,如果你问速度表示什么,那让我来给你画一个常见的场景
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
You see how long you are in the air and the whole time you are in the air, you are traveling horizontally at this speed.
你可以知道在空中停留的时间,当你在空中运动的时候,你一直以这个水平速度在运动
You will find that objects that are at constant initial velocity maintain the velocity.
你也会发现原本匀速的物体,依然保持原来的速度
And yet, you want to talk about the velocity right now.
现在你想讨论当前时刻的速度
A clock tells you what time it is, but you can also say what time it is by seeing how fast the particle is moving because you know it started with some speed.
时钟能告诉你现在的时间,但你也可以通过测量质点速度,来判断当前的时间,因为你知道它的初速度
If I gave you the location of a particle as a function of time, you can find the velocity by taking derivatives.
如果我给出物体的位移是时间的函数,你可以通过求导来得到速度
All velocities I see you will add a certain number to get the velocities according to you.
而我观察到的速度,你也要给它加上某个数值,来得到你观察到的速度
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
For example, if you're talking about the chalk--if I throw the chalk, you will have to know where it is and how fast it's moving.
比如说,这支粉笔,如果我扔出这支粉笔,你就像知道它的位置和速度
Because any velocity I ascribe to a particle or an object, you will add a certain constant to it by the law of composition of velocity.
因为我描述的任何一个质点或者物体的速度,你都要根据速度叠加法则,给它加上某个常数
So, when I threw that thing up and you caught it, what you are doing mentally was immediately figuring out where it started and at what speed.
所以当你接住我抛出的物体时,你大脑里的反应就是,立刻弄清它的初位置以及初速度
Another thing you can do is you can find the speed here.
你能做的另一件事就是你可以求出这里的速度
At any point on the graph you can take the derivative, which will be tangent to the curve at each point, and its numerical value will be what you can call the instantaneous velocity of that point and you can take the derivative over the derivative and call it the acceleration.
在图上的任意一点,你可以进行求导,得到曲线上每一点的切线斜率,所得到的数值,即为该点处的瞬时速度,然后你再求一次导,得出它的加速度
But things which were at rest will move at a constant velocity, opposite of the velocity that you have relative to me.
这些静止的东西都在匀速运动,方向正好跟你相对我运动的速度方向相反
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