摩擦力是高一阶段学习的三种常见的力中方向最难判断的一种,摩擦力的方向总是与相对运动或相对运动趋势的方向相反。在具体运用时,许多同学判断不准确,这是因为通常情况下我们谈到物体的运动、静止都是默认以地球或地面上静止的物体为参照物,使学生对“相对运动或相对静止”与“运动和静止”的概念相混淆,从而不能正确判断摩擦力的方向。摩擦力不仅在高一阶段是重点,而且在后面的电场、磁场中也经常用 Friction is the most difficult to judge one of the three common forces in high-level learning. The direction of friction is always the opposite of the direction of relative or relative movement. Many students make inaccurate judgment when it is used. This is because under normal circumstances, we talk about the movement of objects, and the rest are the default objects on Earth or on the ground as a reference to make students relatively moving or relatively still “Is confused with the concept of ” movement and rest ", and thus can not correctly judge the direction of friction. Friction is not only the key point in the high stage, but also in the electric field and magnetic field