摆线，该摆线的弧长为（ ）。http://image.zhihuishu.com/zhs/onlineexam/ueditor/201812/b9306879dc514d55aad4db73eab6efec.png
举一反三
- 拉普拉斯（Laplace）方程的表达式为（ ）。 A: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201812/26731bcad75f41389448b29292940653.jpg" /> B: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201812/40e7e55a72ee44f59b45d20c84ebe3a6.jpg" /> C: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201812/c65a79ea4d754174b99f34020d6e1735.jpg" /> D: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201812/139e8d3dc37941549e7b6b1731243172.jpg" />
- 平面一维稳定渗流的压力分布公式为（ ）。 A: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201812/d08348f3b84f442d87994311dc13686b.jpg" /> B: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201812/2df214c86c5e4103897ba81ce2c6cd98.jpg" /> C: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201812/cc98e4a778cc463c965ac8115e028f86.jpg" /> D: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201812/bc82177c19d44acfa1b365c3d66ed0a4.jpg" />
- 一质点在平面上作一般曲线运动，其瞬时速度为<img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201812/072ecbf2079c40debf10e59602baef5a.png" />，瞬时速率为<img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201812/a7c386a2ed9641fb872fd3798d8a18d6.png" />，某一段时间内的平均速度为<img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201812/fd7b24d84b0c48b29b905c0accbfb682.png" />，平均速率为<img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201812/25c97028c3294855859e6d26731aecd6.png" />，它们之间的关系必定有（ ） A: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201812/28eb779628f849cb9c561087ac27668c.png" /> B: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201812/332a22fc817749108da3ea994f11c24e.png" /> C: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201812/9fee0e92ea9344e18d11908ba83a7529.png" /> D: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201812/258f415ef0974549b35f450f710027de.png" />
- 图示单元体应力状态，沿x方向的线应变εx可表示为（ ）。 <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201812/9fdd7efe625f4047bb61ef38f5aea871.png" /> A: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201812/5da2d36f7ef84cbc8396b1e27b775bf4.png" /> B: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201812/164a3d85fdb6462696d83d62b92b2435.png" /> C: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201812/9e37e58e1c12442e8e018c0af637dfdf.png" /> D: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201812/41fd81417e5f47bea1db35fed7c2c44e.png" />
- 平面径向活塞式水驱油过程中，纯水区的流量为（ ）。 A: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201812/f8a3355fd37b400b86f9d4e17130c493.png"/> B: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201812/9b416b4e31514c9e9e086fdf179744b1.png"/> C: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201812/08dec96d094b4f039fd625b22fcc376f.png"/> D: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201812/eedcbf5542044303a218a2df52da0771.png"/>