关于单摆振动中的回复力,正确的说法是:(    )A.摆球的重力

 关于单摆振动中的回复力,正确的说法是:(    )

A.摆球的重力        

B.摆球的重力沿圆弧切线方向的分力        

C.摆球的重力和摆线对摆球的拉力的合力      

D.在最底点时,摆球受到的回复力为零,合力也为零

 

答案

 B

 

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