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Homework Help: Fluid Mechanics and SHM of spring

  1. Mar 18, 2012 #1
    1. The problem statement, all variables and given/known data
    Fluid Mechanics problem: http://i.imgur.com/dlAO6.jpg

    SHM of spring problem: http://i.imgur.com/7AOMR.jpg

    2. Relevant equations
    Fluid mechanic problem;
    Bernoulli's principle A1v1=A2v2
    v= velocity
    A= cross sectional area
    R= flow rate

    SHM of spring problem;
    x(t)=Acos(ωt+∅)


    3. The attempt at a solution
    For the Fluid problem I ended up with :
    v = R/A2 = 2R/A1

    For the SHM problem I ended up with:
    A = 0.10
    ∅= cos-10.05/0.1


    I'm having a problem with both of these problems and I'm not confident with my answers.
    Any help would be greatly appreciated :)
    (And sorry if I break any rule of the forums or such, It's only my first post :/ )
     
    Last edited: Mar 18, 2012
  2. jcsd
  3. Mar 18, 2012 #2
    You are going to have to provide a better problem statements than what you supplied. We are not mind readers here.
     
  4. Mar 18, 2012 #3
    I'm sorry :/ These problems are actually made by my professor himself, but I'll try to explain.

    In the first problem, water is flowing from the tank into a narrowing pipe, I'm supposed to get the velocity of the water when its in the narrow part of the pipe. It's related to Bernoulli's principle of fluid through a narrowing pipe.

    For the second problem, It's a block of 0.5 kg displaced 5cm from its original position with an initial velocity of 10 m/s. I'm supposed to get A (or Xm) which is Amplitude and ∅ which is the phase constant.
     
  5. Mar 18, 2012 #4
    In the fluids problem, I think the teacher is looking for an expression for the velocity in terms of the height of the tank.

    A1V1=A2V2 is just a form of the continuity equation which is a statement of conservation of mass for constant density. Bernoulli's principle is something else.
     
  6. Mar 18, 2012 #5
    With the SHM problem, how did you do it without knowing the spring constant value?
     
  7. Mar 18, 2012 #6
    ^This. I was wondering how you could solve without the spring constant.
     
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