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Homework Help: Filling a Pool

  1. Apr 26, 2006 #1
    A 5/8-inch diameter hose is used to fill a round pool 7.2 m in diameter. How long will it take to fill it to a depth of 1.5 m if water leaves the hose at 0.28 m/s?

    [tex]V_{pool} = \pi(3.6)^2 \cdot 1.5 = 61.1 \mbox{m}[/tex]

    [tex]5/8 in = 0.127m, r_{hose} = 0.063.5[/tex]

    [tex]V/s = \pi(0.063.5)^2 \cdot 0.28 = 8.9 \cdot 10^{-3}[/tex]

    [tex]\frac{61.1}{8.9 \cdot 10^{-3}} = 6865.2 s = 2 h[/tex]

    Look ok?
     
    Last edited: Apr 26, 2006
  2. jcsd
  3. Apr 27, 2006 #2

    tony873004

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    no.
    0.127m = 5 inches, not 5/8 of an inch.
     
  4. Apr 27, 2006 #3
    :rofl: that would make sense. I guess my converter doesn't like fractions.

    Besides that, is the method ok?
     
  5. Apr 27, 2006 #4
    Hmm... I get 13 days if I fix the conversion (d = 0.0159m.) This seems like a bit much.
     
    Last edited: Apr 27, 2006
  6. Apr 27, 2006 #5

    nrqed

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    The method sounds right to me.
    This is a huge pool to be filled with a tiny hose!! several day si snot surprising to me.
     
  7. Apr 27, 2006 #6
    The hose is 5/8 inch diameter, not radius. But yes, the method works withthe correct numbers.
     
  8. Apr 27, 2006 #7
    Alright, thanks!
     
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