高中《物理》第二册 (必修 )第 1 4面有这样一道“思考与讨论”题 :图 1中的实线是一列向右传播的横波在图 1某时刻的图象 ;虚线是一段时间Δt(Δt小于介质中质点振动的周期 )后这列波的图象 .介质中的 1、2、3、4各点在朝哪个方向运动 ?这是一道已知横波图象和波的传播方向 , There is such a “thinking and discussion” on the 1st face of the second volume (required) of the “Physics” of the high school. The solid line in Fig. 1 is an image of a row of transverse waves propagating to the right at a certain moment in Fig. 1; the dotted line is a period of time. Δt (Δt is smaller than the period of the medium’s vibration in the medium) after the image of this wave. Which of the 1, 2, 3, and 4 points in the medium is moving in which direction? This is a known wave image and the propagation direction of the wave. ,