当地震发生，它会从震源产生一个速度为数公里每秒的扩散的波。

When an earthquake occurs, it generates an expanding wavefront from the earthquake hypocenter at a speed of several kilometers per second.

youdao

这个成分，是vcosθ,我们叫做径向速度-,等于-100，公里每秒。

So it is this component, v cosine theta - which we call the radial velocity-- that is minus 100 kilometers per second.

youdao

这个爆炸，超新星的爆炸,以高速抛出,行星的外层,速度是一千公里每秒，甩到宇宙空间里，这就是你们所看到的。

The explosion, the supernova explosion throws the outer layers of the star with a huge speed some 10,000 kilometers per second into space, and that is what you are seeing.

youdao