竖立的圆筒形转笼，半径为R，绕中心轴OO＇转动，物块A紧靠在圆筒的内壁上，物块与圆筒间的摩擦系数为μ，要使物块A不下落，圆筒转动的角速度ω至少应为<img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201802/89f0a85f81ed4ec098b93d0d55ce31ba.png" /> A: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201802/79bff9228f8b44a8a991dc5ea15bd1dc.png" /> B: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201802/3d95ab9efaf9495eb3dc5095875dcb62.png" /> C: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201802/72b61163487846fab5c581b986a3e171.png" /> D: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201802/fc10477bb0e64eea9f0a23717ea615d2.png" />

2022-06-17

竖立的圆筒形转笼，半径为R，绕中心轴OO＇转动，物块A紧靠在圆筒的内壁上，物块与圆筒间的摩擦系数为μ，要使物块A不下落，圆筒转动的角速度ω至少应为<img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201802/89f0a85f81ed4ec098b93d0d55ce31ba.png" /> A: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201802/79bff9228f8b44a8a991dc5ea15bd1dc.png" /> B: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201802/3d95ab9efaf9495eb3dc5095875dcb62.png" /> C: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201802/72b61163487846fab5c581b986a3e171.png" /> D: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201802/fc10477bb0e64eea9f0a23717ea615d2.png" />

竖立的圆筒形转笼，半径为R，绕中心轴OO＇转动，物块A紧靠在圆筒的内壁上，物块与圆筒间的摩擦系数为μ，要使物块A不下落，圆筒转动的角速度ω至少应为

A:

B:

C:

D:

答案：

A

举一反三

内容

0
设<img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201808/bed4f91f4fec44358e1cad3163fc6b90.png" />是在区间<img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201808/a58a11f71a434f2ab38a2f347802f010.png" />上的<img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201808/a392447e03794318affaa2b03bb5967b.png" />的分段线性插值函数，以下条件不是<img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201808/c00fe77a8291453a8cb2577eb68735ad.png" />必须满足的条件是________________. A: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201808/cf6e811a4488413fae8f1839e4d098ea.png" /> B: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201808/bb93b2d7d02245878ec51e2986c97b5d.png" /> C: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201808/ec6692c00c2e49b6adbf9b0493638b81.png" /> D: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201808/214f277da4154f58a43751f80b09d959.png" />
1
下列配合物属于螯合物的是（） A: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201906/8f51868d3100497c9f78fe09ba550e3f.png" /> B: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201906/025b639d0fe9456997a0191bdeb0019a.png" /> C: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201906/154fd181ff4d421d96ab4d50e3052020.png" /> D: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201906/fbd3f97989994e40a247c9ea17663bd0.png" />
2
逻辑函数F(A,B,C)=AB+BC+AC的卡诺图为（）。 A: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201809/7a8254757f8a4fc6ab82fa93a8e86ebf.png" /> B: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201809/229cbcade3654fb99c66a7c102ec046f.png" /> C: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201809/1c851f1288be499c92d2a7b40607bd1a.png" /> D: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201809/3b385269839a45df9645db71096c2e81.png" />
3
若x2+y2=1，则dy为（） A: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201905/d045b5f235a54083ab91e6f717cf00d8.png" /> B: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201905/74173c5355234874ab8cb9275865d5d6.png" /> C: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201905/bbfb37ba58fc4de0aa8688e0bb53cef5.png" /> D: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201905/f9a206c25e8c4ea1bd7b51519afd76b7.png" />
4
已知串联支路为<img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201902/65b91bc067d14873a38d0c4675b53329.png"/> ，，则其传递函数为（） A: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201902/8bc361d7b437451dac5c0c42c3213311.png"/> B: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201902/7db9751653e24eba9f152b6937c8c256.png"/> C: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201902/a4b7ab7e122b40068ce6b78635486bae.png"/> D: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201902/a6b34e5a8a764d5c9b78c725d7b77ed4.png"/>