如图6所示,小球和小木块通过轻细绳悬挂在光滑的定滑轮上,小球

如图6所示,小球和小木块通过轻细绳悬挂在光滑的定滑轮上,小球与光滑墙壁相接触,杆一端连接小球,一端通过铰链连接在墙上,已知,小球与小木块的质量关系为m1=m2,则小球所受的力的个数为           (    )

A.5个                           B.4个                 C.3个                    D.2个

 

答案

C

解析:

 

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