2 [多选题]已知一沿x轴正向传播的平面简谐波,时间 |=O 时的波形如图所示,且 =2s ,则以下比算结果正确的得[ 】-|||-y/cm 个-|||-10-|||-C-|||-x/m-|||--5 20m-|||-x=10m =0.1cos (pi t-dfrac (7pi )(6))-|||-说胞的波比方体力 =0.1cos [ pi (t-dfrac (x)(20))+dfrac (2pi )(3)] =-|||-O点的振动万程为 。cdot 0.1cos (pi t-dfrac (2pi )(3)) .-|||-x=10m 处质点级放的M为 =-0sin (pi +dfrac (pi )(6))