如图，一光滑大圆环固定在桌面上，环面位于竖直平面内，在大圆环上套着一个小环，小环由大圆环的最高点从静止开始下滑，在小环下滑的过程中，大圆环对它的作用力_刷题宝

题干

如图，一光滑大圆环固定在桌面上，环面位于竖直平面内，在大圆环上套着一个小环，小环由大圆环的最高点从静止开始下滑，在小环下滑的过程中，大圆环对它的作用力（　　）

A：一直不做功

B：一直做正功

C：始终指向大圆环圆心

D：始终背离大圆环圆心

上一题下一题 0.0难度选择题更新时间:2017-04-03 08:01:41

答案(点此获取答案解析）

A

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