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Homework Help: Picking a chain from one end

  1. Oct 10, 2008 #1
    1. The problem statement, all variables and given/known data
    You have a chain of length 10m with 80kg, how much work does it take to lift this chain from one end to 6ft?


    2. Relevant equations

    [tex]\delta = \frac{10}{80} = .125[/tex]


    3. The attempt at a solution

    [tex]W = \int{F(x)}\,dx = \int^{6}_{0}{\delta lg}\,dl = \frac{\delta l^2g}{2}[/tex]

    I dont think that is right though
     
  2. jcsd
  3. Oct 10, 2008 #2

    Redbelly98

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    So far so good, you just need to evaluate the integrated expression at the integral's limits.

    Is it 6 ft or 6 m?
     
  4. Oct 10, 2008 #3
    Oh whoops! Everything that denotes length is in feet
     
  5. Oct 10, 2008 #4

    Redbelly98

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    Okay. I'm wondering about the "kg" too then.
     
  6. Oct 10, 2008 #5
    I don't really remember the problem so well. But the inherent integral should be the same, no? Unless you refer to lbs as weight or something.
     
  7. Oct 10, 2008 #6

    Redbelly98

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    Yes, the inherent integral is the same. Using lbs can get a little confusing since lbs are a force unit, not mass.
     
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