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Homework Help: Work Problem

  1. Feb 3, 2010 #1
    1. The problem statement, all variables and given/known data

    A rope is 5 meters long and hangs over the edge of a well. It has a bucket of water weighted 20 kilograms attached to one end. For Simplicity, use g=10N/kg

    Suppose the rope has a uniform density of [tex]\rho[/tex] = 1kg/m

    2. Relevant equations

    W=[tex]\int[/tex] F(x)xdx


    3. The attempt at a solution

    I could not figure out what the force would be I would think it would be (Mrope+Mbucket)g
    Mass of the rope would be ([tex]\rho[/tex])(v)=Mrope
     
  2. jcsd
  3. Feb 3, 2010 #2

    tiny-tim

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    Homework Helper

    Welcome to PF!

    Welcome to PF! :smile:

    (have a rho: ρ and an integral: ∫ :wink:)

    Does the question ask for the work done in raising the bucket 5 m ?

    If so, remember that the rope doesn't rise 5 m … it stops as it gets to the top.

    Use work done = change in PE. :wink:
     
  4. Feb 3, 2010 #3
    I know I can do change in PE but this is for my calculus and my teacher wants me to use calculus I did some more work and found this so far. F(y)=(Mrope+Mbucket) Mrope=[tex]\rho[/tex]v. Now I have to find change in y for that I got (5-y) Now my equation for work is the integral from 0 to 5 of ([tex]\rho[/tex]y+20)(5-y)
     
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