弹力突变问题在高中物理教学中既是重点,也是难点。分析物体在某一时刻的瞬时加速度,根据牛顿第二定律确定力和加速度的瞬时对应关系,关键是分析该时刻物体的受力情况及运动状态,再由牛顿第二定律求出瞬时加速度。为此我们必须掌握以下两种基本物理模型:图1轻绳模型,图2轻弹簧模型。 The problem of sudden change in elasticity is not only the focus but also the difficulty in high school physics teaching. According to the second law of Newton to determine the instantaneous corresponding relationship between force and acceleration, the key point is to analyze the force situation and the state of motion of the object at that moment, and then find the instantaneous acceleration by the second law of Newton. To this end, we must grasp the following two basic physical model: Figure 1 light rope model, Figure 2 light spring model.