• 2021-04-14
    管径d=125px,管长L=6m的水平管中有比重为0.9油液流动,水银差压计读数为h=355px,三分钟内流出的油液重量为5000牛顿。管中作层流流动,油液的运动粘度ν为( )。http://image.zhihuishu.com/zhs/onlineexam/ueditor/201901/3efe557b0a69405c8c7556991997e87e.png
  • 1.597×10-4m2/s

    举一反三

    内容

    • 0

      利用毛细管测定油液粘度,已知毛细管直径d=4.0mm,长度L=0.5m,流量Q=25px3/s时,测压管落差h=375px。管中作层流动,油液的运动粘度为(    )。[img=199x166]17a3dcb618978b7.png[/img]

    • 1

      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" />

    • 2

      米糠油在管中作层流流动,若流量不变,管径不变,管长增加一倍,则摩擦阻力损失为原来的()倍;米糠油在管中作层流流动,若流量不变,管长不变,管径增加一倍,则摩擦阻力损失为原来的()倍。

    • 3

      米糠油在管中作层流流动,若流量增大一倍,管径、管长不变,则摩擦阻力损失为原来的( )倍。 A: 2 B: 4 C: 6 D: 8

    • 4

      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" />