兩個(gè)相互接觸的物體,當(dāng)它們要發(fā)生或已經(jīng)發(fā)生相對(duì)運(yùn)動(dòng)時(shí),就會(huì)在接觸面產(chǎn)生一種阻礙相對(duì)運(yùn)動(dòng)的力,這種力叫做摩擦力.說(shuō)明:(1)摩擦力的產(chǎn)生條件:①兩物體必須相互接觸;②相互擠壓的兩物體之間有相對(duì)運(yùn)動(dòng)或相對(duì)運(yùn)動(dòng)趨勢(shì);③接觸面 (共 750 字) [閱讀本文] >>