贵刊今年第5期发表了刘向华老师的《有关圆周运动问题的讨论》一文,文中讨论了自然界中一种常见的运动——圆周运动,根据圆周运动所涉及的知识内容把圆周运动的问题分为三类,并举例说明解圆周运动问题的一般思路和方法,这对培养和提高学生的思维能力确有很大帮助,我们知道,物体做圆周运动需要有向心力的作用,而向心力是一个效果力,它可由重 In the 5th issue of your magazine this year, Professor Liu Xianghua published the article “Discussions on the Circular Circumstances Problem”. This article discusses a common movement in the natural world—circular motion. According to the knowledge content involved in the circular motion, the problem of circular motion is divided. For the three categories, and examples illustrate the general ideas and methods of solving the problem of circular motion, which is very helpful in cultivating and improving students’ thinking ability. We know that the circular motion of an object needs the effect of centripetal force, and the centripetal force is an effect. Force, it can be heavy