1·We call these internal forces.
我们称之为内力。
2·We call them internal forces.
我们称为内力。
3·That's all internal forces.
它们都属于内力。
4·Internal forces don't matter no matter what happens.
系统内力不计，无论发生了什么。
5·And all the internal forces you can forget about it.
而所有的内力，你可以忽略它。
6·The miracle is that all these internal forces eat each other up.
奇迹就是，所有内力相互抵消。
7·This explosion is only internal forces, and so you can write down...
爆炸属于内力，你可以写下。
8·When they collide, you better believe it that there are internal forces.
当它们碰撞，你们必然相信，有内力存在。
9·The net force is ultimately the sum of the external force and all the internal forces.
合力是最终的总和，外力与所有内力总和。
10·As the yarn is twisted, internal forces are built up in the direction of the twist.
当纱线被加捻的时候，在捻度的方向上也会相应地形成内应力。