如图，虹吸管从水池引水至C端流入大气，若不计损失，若B点绝对压强水头下降到0.24m以下时，将发生汽化，设C端保持不动，问欲不发生汽化，a的最大高度等于（ ）。（大气压为10m水柱）http://image.zhihuishu.com/zhs/onlineexam/ueditor/201901/77bb965c39cc4968b918b241cf44490e.png
举一反三
- 如图，大水箱中的水经水箱底部的竖管流入大气，竖管直径为d1＝200mm，管道出口处为收缩喷嘴，其直径d2＝100mm，不计水头损失，A点相对压强pA等于（ ）。http://image.zhihuishu.com/zhs/onlineexam/ueditor/201901/39658bdd7b4e4051a38ad879237111ab.png
- 如图，左边开口测压管和右边真空测压管的水柱高度之差约为（ ）m。http://image.zhihuishu.com/zhs/onlineexam/ueditor/201901/3563a3321f614daaa93b5ec6fb28d07c.png
- 如图，由水池通过等直径虹吸管输水，A点为虹吸管进口处，HA＝0；B点为虹吸管中与水池液面齐高的部位，HB＝6m；C点为虹吸管中的最高点，HC＝7m；D点为虹吸管的出口处，HD＝4m。若不计流动中的能量损失， A、B、C各断面上的相对压强分别为（ ）。http://image.zhihuishu.com/zhs/onlineexam/ueditor/201901/b236cb3459034763acb5baafc1136781.png
- 如图，等直径管，考虑损失，A-A断面为过流断面，B-B断面为水平面，试确定1、2、3、4各点的物理量有以下关系（ ）。<img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201901/221f6e4fdefe4fc8a4dccb77b349aa72.jpg" /> A: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201901/ace37017ba8545728a2182f386058ba6.png" /> B: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201901/70b91bd905944a2b94af05cde3e27218.png" /> C: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201901/2000acab49234b1b95b2c3ecc59dfd3c.png" /> D: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201901/3d47348e1e6f46a99ed44f691c648298.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" />