一根手指的弹击足够使一个气球加速离去，当气球运动时，一点动力，甚至空气的摩擦力可以很快使它慢下来。
The flick of a finger is enough to make a balloon accelerate away. When moving, it has little momentum and even the friction of the air quickly slows it up.
木板哪怕沾了一点水，局部的摩擦系数就会改变。
A little bit of water on the plank would locally make the friction coefficients larger.
到了某个点，“压力压倒了摩擦力，”进行这次地质勘察的地球物理学者Ross s . Stein说，然后断裂就产生了。
At some point, said Ross s. Stein, a geophysicist with the geological survey, "the stress overwhelms that friction," and a rupture occurs.
应用推荐