The period, which is 2 pi times the square root of l over g, if you substitute in your length of 5.1 meters, you will find 4.57 seconds.

周期，等于2π,乘以l/g的平方根，如果把长度为5。1米,代入，会得到4。57秒。

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Using the same two initial arm lengths an Angle of 90 degrees between them produces a third side which is the square root of 2 times the arm length.

使用最初的相等的两个手臂长度和之间的夹角为90度，可以产生第三条边，而变成等于2的平方根乘以手臂的长度。

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Now you have to know from elementary calculus that v times dv/dt is really d by dt of v square over 2.

根据初等微积分知识你们得知道,v乘以dv/dt其实就是d/2)/dt

耶鲁公开课 - 基础物理课程节选

As long as we understand that, we can do this cancellation and this says on the left-hand side the change in the quantity v square over 2 is a times the change in the quantity x.

只要我们明白这一点,我们就可以这样做简化,在等号左边,v^/2的变化量,为a乘以x的变化量

耶鲁公开课 - 基础物理课程节选

An estimated 12, 000 people attended the event, which took place in Times Square between 28 February and 2 March.

BBC: Street Spice salmonella outbreak: Online survey

Among its highlights are Tokyu Hands (Takashimaya Times Square, 5-24-2 Sendagaya), a department store that sells everything you could ever need, and plenty of stuff you had no idea even existed (electrically heated pilllows anyone?).

CNN: Tokyo: Where to shop