如图所示，可绕 O 点转动的轻质杠杆，在 D 点挂一个重为 G 的物体 M ，用一把弹簧测力计依次在 A ， B ， C 三点沿圆 O 相切的方向用力拉，都使杠杆在水平位置平衡，读出三次的示数分别为

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如图所示，可绕 O 点转动的轻质杠杆，在 D 点挂一个重为 G 的物体 M ，用一把弹簧测力计依次在 A ， B ， C 三点沿圆 O 相切的方向用力拉，都使杠杆在水平位置平衡，读出三次的示数分别为 F1 F2 、 F3 ，它们的大小关系是（）

A： $F_{1} < F_{2} < F_{3} < G$

B： $F_{1} > F_{2} > F_{3} > G$

C： $F_{1} = F_{2} = F_{3} = G$

D： $F_{1} > F_{2} = F_{3} = G$

上一题下一题 0.0难度选择题更新时间:2012-01-10 01:16:12

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C

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