在学习了“力”的概念与“二力平衡”的知识后 ,一些同学对于力的作用是相互的及二力平衡的理解不够深入。比如 ,常有这样的判断题 :大小相等 ,方向相反 ,作用在一条直线上的两个力一定是平衡力。不少学生认为这句话是正确的。为什么会出现这样的错误呢 ?根本原因就在于他们将 After learning the concept of “force” and the knowledge of “two forces balance”, some students did not thoroughly understand the mutual effects of force and the balance between the two forces. For example, there are often such judgment questions: equal in size, opposite in direction, and the two forces acting on a straight line must be balance forces. Many students think this sentence is correct. Why is this kind of mistake? The root cause is that they will