举一反三
- 物体与水平面的摩擦角，其上作用有P与Q两力，且P=Q，则物块所处的状态为（）。
- 中国大学MOOC: 物体与水平面的摩擦角φm=20°，其上作用有P和Q两力，且P=Q，两力夹角30°则物体所处的状态为http://edu-image.nosdn.127.net/D3FD48817032E4653C284E609FA9E4CC.png?imageView&thumbnail=890x0&quality=100
- 物块重P，放在粗糙的水平面上，其摩擦角jf，若力作用于摩擦角之外，并已知，F=P，物体是否能保持静止____。http://image.zhihuishu.com/zhs/onlineexam/ueditor/201812/eb9ddb3c00734774831109c20482d10c.png
- 物块重5kN，与水平面间的摩擦角为jf，今用与铅垂线成角的力推动物块，若F=5kN，则物块_______。http://image.zhihuishu.com/zhs/onlineexam/ueditor/201812/c159f046107d47369fe4de8d2f743eab.png
- 力 作用在 OABC 平面内， x 轴与 OABC 平面成 q 角（ ），则力 F 对三轴之矩为 __ ___________ 。http://image.zhihuishu.com/zhs/onlineexam/ueditor/201812/b56e7eb2adca4d6b8689f328d472fdbc.png
内容
- 0
图示物块重量为Q，与水平面之间的摩擦系数为f=0.35，则拉动物块所需水平力P的最小值为（）。 A: P=0.3Q B: P=0.35Q C: P=0.5Q D: P=Q
- 1
船A重P<sub>A</sub>，以速度 <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201812/1e6a475774084108a4d9ded2c70e6ca1.png" />航行。重P<sub>B</sub>的物体B以相对于船的速度<img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201812/b39c5c7163f846e8bc34287ec16ef1a7.png" />空投到船上，<img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201812/20f0fb6f6dbc40638b69c7a33e96fd41.png" />设与水平面成<img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201812/3651093fa407458596d5b85ce9b1dc5d.png" />角，且与<img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201812/14fe1be64d75470c8843680bac3209a7.png" />在同一铅直平面内。若不计水的阻力，则二者共同的水平速度为____________。<img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201812/9456cc95f694413584344f4bad82d008.png" /> A: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201901/910e6572478f418c97aa55ae3e71eb87.png" /> B: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201901/eb921b41a733425c811ac7b3848f3afe.png" /> C: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201901/06d430260f9c402eaf641a0ba96427c5.png" /> D: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201901/4c6f547166aa4497b9c6e8ff20fb5407.png" />
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已知P=100N，F=80N，静摩擦因数fs=0.2，物块将______。http://image.zhihuishu.com/zhs/onlineexam/ueditor/201812/ad33c7634e564c23be1cd18f76f6fd7b.png
- 3
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" />
- 4
体心立方结构金属晶体的的密排面为（ ）， 密排面晶面间距为（ ）。 A: （110） B: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201808/b9f806bad3874ceca9c758a3b0107652.png"> C: （111） D: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201808/80eebcaaf36e4af084acf1e4d07e1acf.png"> E: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201808/dc64bdb4cb04403097873133316c57a8.png"> F: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201808/1b1c162777d04e51bd02eb8f92094b84.png">