下列说法正确的是( )    A.静摩擦力有最大值,说明静摩擦

下列说法正确的是(  )

    A.静摩擦力有最大值,说明静摩擦力在一定范围内是可以改变的

       B.相对静止的物体间一定有静摩擦力的作用

       C.物体受静摩擦力作用时,一定处于静止状态

       D.若物体间有摩擦力就一定有弹力

      

答案

解析:物体间是否有弹力是摩擦力产生的必要条件,物体间是否有相对运动或相对运动趋势是摩擦力产生的充分条件.

答案:AD

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