The object particle means to the microcosmic particle that its static mass is not zero, for example, electron atom molecule and so on.

实物粒子是指静止质量不为零的微观粒子，如电子、原子和分子等。

youdao

Because any velocity I ascribe to a particle or an object, you will add a certain constant to it by the law of composition of velocity.

因为我描述的任何一个质点或者物体的速度,你都要根据速度叠加法则,给它加上某个常数

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