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。

麻省理工公开课 - 固态化学导论课程节选

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。

麻省理工公开课 - 化学原理课程节选

Well, we say at the top of the loop, when it goes up and comes down the velocity is 0.

在曲线顶端,当物体上升,然后速度为0时候

耶鲁公开课 - 基础物理课程节选

A 100% uncertainty in the position 15% gives rise to a 15% uncertainty in velocity.

从完全不确定的位置,到速度的不确定度为。

麻省理工公开课 - 固态化学导论课程节选

It's sort of pick up and has averaged about 6% 6% for about...for the last 25 years.

这时才开始迅速发展%,在最近的25年平均增长速度为。

普林斯顿公开课 - 国际座谈会课程节选

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。

耶鲁公开课 - 死亡课程节选

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。

斯坦福公开课 - 7个颠覆你思想的演讲课程节选

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。

麻省理工公开课 - 化学原理课程节选

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。

麻省理工公开课 - 化学原理课程节选

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

耶鲁公开课 - 基础物理课程节选

I agree, but I want the speed in meters per second.

我同意,但我希望速度以米每秒为单位

耶鲁公开课 - 基础物理课程节选

That's the point where velocity is 0.

也就是速度为零的点

耶鲁公开课 - 基础物理课程节选

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

耶鲁公开课 - 基础物理课程节选

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

耶鲁公开课 - 基础物理课程节选

Even at=0, and it has an initial velocity, so even without any acceleration, it will be moving from y0 to y0+vt.

即使at=0,它仍然有初速度,因此即使加速度为0,它也会从y0运动到y0+vt

耶鲁公开课 - 基础物理课程节选

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

耶鲁公开课 - 基础物理课程节选

It's gaining speed at some rate a.

速度的增长速率为a

耶鲁公开课 - 基础物理课程节选

So, we know in this example the initial height should be 15 meters and the initial velocity should be 10, and for acceleration, I'm going to use -g and to keep life simple, I'm going to call it -10.

我们知道在这个例子中,初始高度为15米,初始速度为10,然后是加速度,我们用"-g"表示重力加速度,为了计算方便,加速度的值取为-10

耶鲁公开课 - 基础物理课程节选