如图所示，每个滑轮的重为100N，不计摩擦与绳重，用此滑轮组将500 N的重物匀速提升 l m．在此过程中 ( )_刷题宝

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如图所示，每个滑轮的重为100N，不计摩擦与绳重，用此滑轮组将500 N的重物匀速提升 l m．在此过程中 ( )

A：拉力F的最大值是350N　　

B：拉力F所做的功一定是900 J

C：拉力F通过的最小距离为3 m

D：滑轮组的机械效率一定是83.3％

上一题下一题 0.0难度选择题更新时间:2014-02-14 05:05:50

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D

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