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> 如图所示，质量均匀的球夹在光滑竖直墙面和光滑轻板之间，轻板可绕其L端的水平轴O自由转动。在轻板上端用竖直向上的拉力 F提着轻板，使其缓慢放下，直到轻板呈水平之前， F的大小以及 F对于轴O的力矩 M的大小变化情况是（） A．F减小，M减小 B．F减小，M不变 C．F增大，M增大 D．F增大，M减小

问题：

发布时间：2024-09-12

如图所示，质量均匀的球夹在光滑竖直墙面和光滑轻板之间，轻板可绕其L端的水平轴O自由转动。在轻板上端用竖直向上的拉力 F提着轻板，使其缓慢放下，直到轻板呈水平之前， F的大小以及 F对于轴O的力矩 M的大小变化情况是（）

A．F减小，M减小 B．F减小，M不变

C．F增大，M增大 D．F增大，M减小

参考答案：

提问用户：mn***v8B

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