传送带问题复杂多变,但其中的核心问题是摩擦力的性质和摩擦力方向的判断,特别要注意摩擦力的动静互换,从有到无临界点的判断·其实把其中一种情况分析透,其他问题就迎刃而解了·总体来说,传送带问题是把物体由静止、以一定的速度 The problem of conveyor belt is complicated and changeable, but the core issue is the judgment of the nature of friction and the direction of friction. Special attention must be paid to the exchange of friction and friction, from the judgment to the non-critical point. In fact, , The other problems are solved. In general, the problem of the conveyor belt is to move the object from rest to a certain speed