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A question about fluids and tubes

  1. Aug 27, 2015 #1
    My physics teacher cooked up an experiment today on the fly where we tried to calculate the horizontal distance traveled, D, from a rubber tube through which water was siphoned from a graduated cylinder elevated a certain distance H from the ground:
    He modified an experiment he had found of the same sort but with a hole in the cylinder instead, in which case he could use Torricelli's Law to find that [itex]v=sqrt(2gh)[/itex] for water exiting with the surface a distance of h above the hole and basic kinematics to find the horizontal distance upon impact with the ground. We tried the same equations with h being the height of the tube above the opening and the calculations gave a distance that was much farther than the actual distance. What is the proper way to go about this problem and why did the application of the same equations give such a gross overshoot?
  2. jcsd
  3. Aug 27, 2015 #2


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    How does flow through a tube differ from flow through an orifice?
  4. Aug 27, 2015 #3


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    So what you are saying is that if you move the top curve of the siphon higher or lower, using the "same equations" the distance d should vary?
    Seems that you have forgotten something about the hose.
  5. Aug 28, 2015 #4
    Evidently I have forgotten something, but I don't know what it is. I'm not exactly sure what is different between flow out of an orifice and a tube.
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