The positive phase dynamic impulse can be defined by a similar expression. 正周相動(dòng)力沖量的定義可以用類(lèi)似的式子表示。
We shall see next how two similar concepts, those of impulse and momentum, also arise from these laws. 下面我們將看到兩個(gè)相似的概念,即沖量和動(dòng)量,也是從這些定律引伸出來(lái)的。