解： y=0.05cos(10πt-4x) 与 y-Acos(R2Ivt-2Tx) 比较得 (1)A=0.05mv=5Hz 九=0.5m u=λy=0.5×5=2.5m/s (2) um=Aw=0.05×10r=0.5Tm/s am=Aw2=0.05×(10兀)2=0.52m/s2 结束 目录y = 0.05cos(10πt 4πx ) A =0.05m n =5Hz l =0.5m um =Aω=0.05×10π=0.5πm/s am =Aω2 0.05×(10π) 2 = =0.5π2 m/s2 u= ln =0.5×5=2.5m/s 解： n π l y = Acos(2 t π ) 2 与 x 比较得 (1) (2) 结束 目录