纯滚动轮所受静摩擦力方向的确定

The Determine of the Static Friction Direction of a Pure Rolliog Wheel

当轮作纯滚动时,静摩擦力不作功,但是,可以分别相对于轮的转动与平动这两种基本运动作功,这两种功一正一负、数值相等,静摩擦力所起的作用是实现转动动能与平动动能之间的能量转换.根据这一规律,得出判断纯滚动轮所受静摩擦力方向的原理.对若干典型的纯滚动轮所受静摩擦力方向确定的问题进行分析.

When a wheel in the stat of pure rolliog motion, the static friction force does not make the work,but it can be compared with each round of rotation and translation of these two basic movments for power,one of which is negative and the other is positive,and the value is equal,the role of the static friction force is to realize the conversion between the rotation kinetic and the stable motion kinetic energy energy. According to this rule,that judge suffers pure rolling round the direction of the principles of static friction. The paper also analyzes the problems of a number of a typical round of pure rolling friction suffers static direction of the issues identified.