一、教材中的演示实验单摆做小角度(摆角θ≤5°)振动时,其振动可视为简谐运动,其振动图像为正弦曲线。教材~([1])中用如图1所示装置来做演示实验:细线下悬挂一个除去了柱塞的注射器,注射器向下喷出一细束墨水。沿着与摆动方向垂直的方向匀速拖动一张白纸,白纸上的墨迹便画出了振动图像(x-t图像)。 First, the textbook demonstration experiment pendulum do a small angle (swing angle θ ≤ 5 °) vibration, the vibration can be regarded as simple harmonic motion, the vibration image is a sine curve. Textbook ~ ([1]) using the device shown in Figure 1 to do the demonstration experiment: a thin line under the suspension of a syringe plunger, syringe down a thin beam of ink. Drag a piece of white paper at a constant speed in a direction perpendicular to the direction of the swing, and the ink on the white paper draws a vibration image (x-t image).