The force of friction slows the spacecraft down as it re-enters the earth's atmosphere.
航天飞机重返地球大气层时因有摩擦力而减慢速度。
《牛津词典》
2
The frictional force remains constant, dependent on the friction, the kinetic friction coefficient, is always the same...
摩擦力不守恒，它取决于摩擦力，动能摩擦系数，一直是相同的。
3
The more rough and jagged something is, the more easily more of its molecules will come into contact with molecules on the surface it touches, and thus the greater force of friction they will exert.