(3)x=0.2mt=1s ①=4兀-4J×02=92π 在原点处x=0 10兀t=9.2兀 t=0.92s 0.05y/mt=12st=1s t=1.25s X/m 结束目录t =1s Φ =4π 4π×0.2 =9.2π 10πt =9.2π (3) x =0.2m 在原点处 x =0 t =0.92s o x/m y/m 0.05 t =1.25s t =1.2s t =1s 结束 目录