题干

如图所示,在光滑水平面上以水平恒力F拉动小车和木块,让它们一起做无相对滑动的加速运动,若小车质量为M,木块质量为m,加速度大小为a,木块和小车间的动摩擦因数为.对于这个过程,某同学用了以下4个式子来表达木块受到的摩擦力的大小,下述表达式一定正确的是

A: F-Ma

B:(M+m)a

C:μmg

D: Ma

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答案(点此获取答案解析)

A

同类题3

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