如右图所示,一物体重500N,滑轮重、绳重和摩擦均忽略不计,要拉

如右图所示,一物体重500N,滑轮重、绳重和摩擦均忽略不计,要拉起这个物体甲图中需____N拉力,乙图中需____N拉力。

答案

500N    250N 

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