圆周上各点离圆心的距离相等。
不要把沿圆周的切向加速度与向心加速度混淆。
Do not confuse ever the tangential acceleration, which is along the circumference, with centripetal acceleration.
假设您想要创建一个放射状的列表框，将其内容沿圆周排列，就像一个旋转木马。
Imagine you want to create a radial list box that arranges its content along a circle, like a carousel.
为了纪念祖，一些数学家建议称圆周率为“祖率”。
In order to remember Zu, some mathematicians suggest calling pi "Zu Lv".
进化论的作者、年轻的英国植物学家查尔斯·达尔文，是第一个看到落叶柏树干圆周长达一百三十英尺的欧洲人。
A young English botanist named Charles Darwin, the author of the theory of evolution, was the first European to see alerces, with trunks that had a circumference of 130 feet.
2010年3月14日：圆周率日。
葡萄酒杯的直径与圆周晃动的宽度的比率；
the ratio of the diameter of the glass to the width of the circular shaking;
他凭记忆背诵圆周率到22 514位。
我们需要把看出一个接一个很小的圆周运动的叠加。
We need to add smaller circular motions on top of each other, and so on.
pai是一个数学常量，代表圆周长跟直径的比值。
It's a mathematical constant representing the ratio of any circle's circumference to its diameter.
在太阳系，大多数的行星都各自拥有统一的圆周轨道。
In our solar system, planets for the most part have fairly uniform circular orbits.
如何解释可见行星并不是，连续不断地做圆周运动呢。
How did they explain the fact that the motion of the planets visibly was not just straight consistent circles.
究竟何物把上帝完美的圆周运动替换成了物质的奋斗呢？
Which instead strives to imitate the perfection of God by moving in circles?
它们都在做着圆周运动，必然以其为奋斗目标。
Well, we see those moving in circles, they must be striving to move in circles.
但是别把这个切向加速度，它是沿着圆周的，和向心加速度混淆。
Do not confuse ever the tangential acceleration, which is along the circumference, with a centripetal acceleration.
匀速圆周运动发生在，当物体沿着一个圆环滚动，速率恒定的情况下。
Uniform circular motion occurs when an object goes around in a circle and when the speed never changes.
我跳起来，旋转，绕着每个星球的圆周行进，玩笑般的对付着地心引力。
I leap, I spin, I navigate the circumference of each spherical planet, toying with gravity.
那是因为，至少在圆周长度方面，我们星球上的一些地方比其他的要大。
That's because some parts of the planet are much bigger than others, at least in circumference.
亚里士多德理论都是基于天堂里的物体，做圆周运动这一基础思想而展开的。
Now, the Aristotelian theory, as I said, was based on the idea that all heavenly bodies basically move in circles.
在纯滚动情况下，Q的速度，和圆周的速度，如果你们看得到-，是相同的。
When we have pure roll, the velocity of this point Q, and the velocity of the circumference, - if you can read that — are the same.
Lehrer：你是如何能背诵圆周率小数点后22514位数的？
LEHRER: How were you able to recite from memory the first 22, 514 Numbers of Pi?
让我设个假设，所有的车轮的物质是在，圆周上的，并不是很准确，但很接近的。
And let me make the assumption that all the mass of the bicycle wheel is at the circumference, which is not very accurate, but it's close to that.
一般一个完美圆周的偏心值为0，而约有一半的系外行星的偏心值在0.25或者更高。
Where a perfect circle has an eccentricity value of zero, roughly half of exoplanets seen thus far have an eccentricity of 0.25 or greater.
然后他很有礼貌地把圆周理论物理研究所的环境比作那些有创新性的强大国家。
He then courteously likened the environment at Perimeter to these powerhouses of innovation.
一开始将电子电荷平方，再除以光速和普朗克常数，然后将总数乘以2个圆周率。
You start with the square of an electron's charge, divide it by the speed of light and Planck's constant, then multiply the whole lot by two PI.
原本是圆周运动，突然间，推力和拉力都没有了，这就会呈螺旋状运动，显然，这是不对的。
You go around in a circle, and all of a sudden you no longer have the pull or the push and you go around in a spiral and obviously, that is not the case.
我们也可以用角度来做参数的，但不是在这个例子里，而是在沿圆周运动或一些类似的情况时使用。
And we could also have used maybe some Angle. Well, not here, but if we had been moving on a circle or something like that.
先前在讲行星时,我们讨论过这个，我们讨论的是,匀速圆周运动，而且我们评估了,向心加速度。
We have discussed that earlier when we dealt with the planets, and we dealt with uniform circular motions, and we evaluated the centripetal acceleration.
这是一个向量场，其中旋转轨道是，以z轴为圆心的圆周，并且这个向量场与每个圆相切。
That is a vector field in which the trajectories are going to be circles centered in the z-axis and our vector field is just going to be tangent to each of these circles.
他会尝试用指关节，用一只手掌根压在另一只手背上，网球，背部按摩器，采用直压按摩或圆周按摩。
He can try his knuckles, the heel of one hand reinforced by pressure from the other hand on top of it, a tennis ball, or a back massager, using direct pressure or a firm circular motion.
应用推荐