在中学物理中,不引入质心的概念及质心定理,但由质心定理得出的结论:“在内力作用下不会改变系统质心的运动状态”却不难掌握,下面,先通过对一个具体同题的简单计算作例证,进而举例说明它的运用。一、简单例证如图1,在光滑水平面上放着质量分别为 m_1、m_2的两个物体,中间放置一根用细线缚住的弹簧(但不与物 In the middle school physics, the concept of centroid and centroid theorem are not introduced, but the conclusion drawn from the centroid theorem: “The motion state of the system center of mass will not change under the influence of the internal force” but it is not difficult to master, below, first through a An example of a simple calculation of the same problem is used as an example to illustrate its use. First, a simple example is shown in Figure 1. Two objects of mass m_1 and m_2 are placed on a smooth horizontal surface, and a spring (but not associated with it) is placed in the middle.