在图示三铰拱结构的两半拱上，各作用等值反向的两力偶M。约束力FRB为 。http://image.zhihuishu.com/zhs/onlineexam/ueditor/201805/5ab0e7e799f548e79ff9a19b0d4f274c.png
举一反三
- 组合梁如图示。已知q=2kN/m ， F=10kN , 求固定端 A 处的约束力偶 M A 等于 。http://image.zhihuishu.com/zhs/onlineexam/ueditor/201805/3dc88c1d09c94a299948b91b63cfed38.png
- 在均匀电场中，作一半径为R的半球面，使半球面的轴与场强E的方向平行，则通过这一半球面的电通量为 A: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201805/bf341a312be54f3c99c3472135e65b4d.png" /> B: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201805/75062c5d50c24d6684010689732915ac.png" /> C: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201805/47e2f56b1f234526a7582ca537740bcc.png" /> D: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201805/5284cd2d979041baaed0b04028cfb72b.png" />
- 图示曲柄连杆机构，已知曲柄OA长L，重量不计，连杆AB长2L，重P，受矩为M的力偶和水平力Ｆ的作用，在图示位置平衡。若用虚位移原理求解，则必要的虚位移之间的关系为___________，力F的大小为_____________________。<img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201901/be06434307bd424abfc4ebfe02661f7a.png" /> A: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201901/b8e7b964d1c84aeca7b22ddef4de87a2.png" />;<img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201901/a584946cde17410c945d6611ff2113b5.png" /> B: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201901/1aaef24e28ee477ab25dae0a400bf23f.png" />;<img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201901/f3b395453e1d48bdadff2e37dfbbb626.png" /> C: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201901/be37912822f0451bb15639b7fa0589f1.png" />;<img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201901/6d1112b5c1b4446b93578138388ed79f.png" /> D: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201901/89b7bcef6b51410cb624a654747d56ee.png" />;<img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201901/0e2b78f437914a1eb8327d13185eaedf.png" />
- 正方体仅受两个力偶作用，该两力偶矩矢等值、反向，即，但不共线，则正方体（ ）。http://image.zhihuishu.com/zhs/onlineexam/ueditor/201808/615ba9fbaf354580a4a4cdb4c069b440.png
- 正方体仅受两个力偶作用，该两力偶矩矢等值、反向，即 ，但不共线，则正方体（ ）。http://image.zhihuishu.com/zhs/onlineexam/ueditor/201808/615ba9fbaf354580a4a4cdb4c069b440.png