滑轮的使用常有竖直放置和水平放置两种形式.同学们接触较多的是竖直放置形式,而对水平放置的滑轮感到陌生,其实,它们的本质是相同的.1.使用动滑轮,要搞清谁是动力,谁是阻力.当使用动滑轮拉物体在水平面上做匀速直线运动时,设物体与地面间的摩擦力为f,若拉力作用在绳的自由端,有Fa=1/2f,则可省力一半,如 The use of pulleys is often vertical and horizontal. The students are exposed to the vertical position, but they are unfamiliar with the horizontally placed pulleys. In fact, their essence is the same. 1. The use of moving pulleys, To find out who is the motive force, who is the resistance. When using the moving pulley to pull the object on the horizontal plane to do a uniform linear motion, let the friction between the object and the ground be f, if the tensile force acts on the free end of the rope, there is Fa=1/ 2f, you can save half, such as