题目内容


沿x轴正向传播的一列简谐横波在t=0时刻的波形如图所示，P为介质中的一个质点，该波的传播速度为2.5m/s，则t=0.8s时（    ）                                                                                                                  

                                                                                              

　   A．  质点P对平衡位置的位移为正值

　   B．  质点P的速度方向与对平衡位置的位移方向相同

　   C．  质点P的速度方向与加速度的方向相同

　   D．  质点P的加速度方向与对平衡位置的位移方向相反

                                                                                                                                      


BD

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