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Homework Help: Need some Help

  1. Apr 9, 2005 #1
    I have two more questions for anyone can help....
    1. A frog in a hemispherical pod finds that he just floats without sinking in a fluid of density 1.25 g/cm3. If the pod has a radius of 9.00 cm and negligible mass, what is the mass of the frog?
    2. A cowboy at a dude ranch fills a horse trough that is 1.6 m long, 60 cm wide, and 40 cm deep. He uses a 1.9 cm diameter hose from which water emerges at 1.4 m/s. How long does it take him to fill the trough?

    Just need some direction...no answer.
     
  2. jcsd
  3. Apr 9, 2005 #2

    dextercioby

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    For the first problem:HINT:The buoyancy force must be equal to the gravity force...

    For the second:what is the colume of the trough?What is the flow through the hose...?

    Daniel.
     
  4. Apr 9, 2005 #3
    I still don't understand how you begin the problem....do you divided 9 cm by 1.25 g/cm^3?
     
  5. Apr 9, 2005 #4
    Firstly, you must understand the definition of The buoyancy force. Do you know what that is and how to calculate it ???

    marlon
     
  6. Apr 10, 2005 #5
    Anyone help?
     
  7. Apr 10, 2005 #6

    dextercioby

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    Yeah.U've been asked 2 questions above.Can u answer them?

    Daniel.
     
  8. Apr 10, 2005 #7
    Yeah, the pod partially submerged in the fluid experiences the bouyant force equal in magnitude to the weight of the fluid displaced by the pod.
    To calculate it B=PfluidVg=wfluid ?
     
    Last edited: Apr 10, 2005
  9. Apr 10, 2005 #8

    dextercioby

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    [itex] F_{B}=\rho_{fluid}V_{body}g [/itex]...

    And u need to know the volume of the immersed body.

    Daniel.
     
  10. Apr 10, 2005 #9
    how do you find the volume of the immersed body?
     
  11. Apr 10, 2005 #10

    dextercioby

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    I can only assume that all the hemisphere is immersed.The problem is not to explicit,so you have to make assumptions,in order to get a result.

    Daniel.
     
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