但是，测量这些物体的速度和距离又是很困难的。

But, again, measuring the speed and distance to these objects is difficult.

youdao

只有当火车的速度和距离改变了，窗玻璃才静止下来。

Only when the train's speed and pitch changed did the windowpane become silent.

youdao

研究表明，男性大脑通过估量速度和距离来知道什么时候转变方向。

Studies show that a man's brain measures speed and distance to know when to change direction.

youdao

So, we can just plug it in. Speed is equal to the distance traveled, which is lambda over the time elapsed, which is 1 over nu. so, we can re-write that as speed is equal to lambda nu times nu, and it turns out typically this is reported in meters per second or nanometers per second.

经过的距离和所花的时间,我们把它们带进来,速度等于经过的距离,也即是lambda除以,所花的时间,通常它的单位,是米每秒或者纳米每秒。

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