静摩擦力是相对静止的接触体之间有相对运动趋势时产生的,其方向与相对运动趋势相反,沿着接触面的切线方向。运动参照物为施加静摩擦力作用的物体。“相对运动趋势”不是物理量,也没有明确的物理含义,仅仅是一种通俗的说法,因而容易造成静摩擦力概念上的模糊,给解决问题带来困难。“相对运动趋势”的物理含义是什么呢?如图1所示的光滑水平面上,m_A=10千克,m_B=20千克,在物体 A 上施加力 F_1,在物体 B 上施加力 F_2,A、B 间静 The static friction force is generated when there is a tendency of relative motion between relatively stationary contact bodies, and the direction thereof is opposite to the relative movement tendency and along the tangential direction of the contact surface. The moving reference is the object that exerts static friction. “Relative movement trend” is not a physical quantity, there is no clear physical meaning, just a popular saying, it is easy to cause the conceptual ambiguity of static friction, to bring difficulties to solve the problem. What is the physical meaning of “relative motion trend”? As shown in Figure 1, on the smooth horizontal surface, m_A=10 kg, m_B=20 kg, force F_1 is applied to object A, and force F_2 is applied to object B. A, B quiet