For the columns with the same length, material, constraint conditions and cross-sectional area, etc., the stability of which kind of shape of cross-section (see the following figures)is best ? . And the stability of which is worst? .http://image.zhihuishu.com/zhs/onlineexam/ueditor/201904/64415e4a30114dd688f87cc28116d571.png
举一反三
- Cross curves of stability show which of the following（）.
- An equal cross-section straight rod is exerted by the loads shown in the figure, the cross-sectional area of the rod is A=100mm2. Determine the normal stress on the cross-section m-k.http://image.zhihuishu.com/zhs/onlineexam/ueditor/201904/23fd5f3f3d6d4bb99e3cc743abf84ff6.png
- The cross-sectional area of each column is the same. Under the same conditions, the stability of the column is the best when the column adopts the cross-sectional shape shown in fig. （ ）.[img=549x158]1803a2588a00e24.jpg[/img] A: （a） B: （b） C: （c） D: （d）
- In the fixedly combined circular shaft shown in the figure, the central part of the material is steel, shear modulus G1=80GPa, the outer material is copper and the shear modulus G2=39GPa. The distribution of shearing stress on cross section is___after torsional deformation. ① ② ③ ④http://image.zhihuishu.com/zhs/onlineexam/ueditor/201904/e48a2be70d9f4eec8d38b0270076b6e2.png
- 理想运算放大器的主要特征为 A: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201904/8ec216c374814f48ad60b00627bee3d6.png" /> B: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201904/b36e9dfc39a748b1b652e9b3c1a762ed.png" /> C: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201904/2a93dfdbeb804030ac0da51eed08943e.png" /> D: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201904/a01ee7baba84489f886c43cc5d5c5169.png" />