下列有关功的说法,正确的是(   )A.只要物体发生了位移,就

下列有关功的说法,正确的是(   )

A.只要物体发生了位移,就一定有力对它做了功

B.凡是受力物体,一定有力对它做了功

C.物体既受了力,又发生了位移,则力一定对物体做了功

D.只有物体在力的方向上发生了位移,力才对物体做功

 

答案

D

解析:

 

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