力学与实践 ›› 2010, Vol. 32 ›› Issue (5): 83-86.DOI: 10.6052/1000-0879-lxysj2010-020

• 教育研究 • 上一篇    下一篇

滚动问题中摩擦力的判断

彭瑞东,周宏伟,黎立云   

  1. 中国矿业大学(北京),,
  • 收稿日期:2010-01-14 修回日期:2010-04-20 出版日期:2010-10-08 发布日期:2010-09-07

The Determine of the Friction Force in Rolling Problems

  • Received:2010-01-14 Revised:2010-04-20 Online:2010-10-08 Published:2010-09-07

摘要: 刚体滚动时摩擦力的判断是工程力学中极易引起学生困惑的问题. 在对摩擦力产生原因进行分析的基础上, 确定了刚体纯滚动时静摩擦力的计算公式和判定方法. 刚体作纯滚动时静摩擦力所作总功为零, 仅实现刚体平动动能和转动动能之间的相互转化, 其方向总是阻碍主动力引起的物体运动趋势并使其向另一种运动转化; 刚体作有滑滚动时滑动摩擦力所作总功为负, 其方向与刚体滑动方向相反, 并实现刚体平动动能和转动动能之间的相互转化.

关键词:

滚动,滑动,摩擦力,纯滚动,功

Abstract: How to determine the friction force of a rolling rigid-body often confused the students who are learning engineering mechanics. The reason that results in the friction force was analyzed, and thenthe equation to determine the static friction force was ascertained. By means of the work-energy principle, the effect of friction force was discovered. It was concluded that the total work of the static friction force of a rolling rigid-body is zero and the total work of the sliding friction force of a rolling rigid-body is negative. The role of the friction force is to realize the conversion between the rotation kinetic and the stable motion kinetic energy. The direction of the static friction force is to prevent the trend of motion due to force, and the direction of the sliding friction force is negative to the direction of sliding movement.

Key words:

rolling, sliding, friction, pure rolling motion, work