有关滑轮、滑轮组的综合题是中考命题的热点,命题者往往通过改变题设的物理情景.使很多同学掉入“陷阱”.下面举例说明.一、改变滑轮、滑轮组的位置例1如图1所示,一人通过滑轮将船拉向岸边,人对绳子的拉力为200N.船以0.2m／s的速度匀速前进.若滑轮的机械效率为80％.求:(1)人拉绳的功率; The comprehensive questions about the pulleys and pulleys are hot topics in the exam topics. Propositions often change the subject’s physical situation. Many students fall into the “traps.” The following examples illustrate. First, change the position of pulleys and pulleys. Example 1 As shown in Figure 1, one person pulls the boat to the shore by means of a pulley, and the man’s pulling force on the rope is 200N. The ship advances at a speed of 0.2m/s at a constant speed. If the mechanical efficiency of the pulley is 80%, find: (1) the person pulls Rope power;