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Homework Help: Work with Friction

  1. Apr 12, 2009 #1
    1. The problem statement, all variables and given/known data
    A boy pulls his wagon of mass 25.0kg at a constant velocity a distance of 20.0m. the wagon's handle makes an angle of 40.0° with the ground while the boy is pulling on it with a force of 60.0N. The coefficient of friction is 0.214. how much work did the boy do on the wagon

    2. Relevant equations


    3. The attempt at a solution

    Not sure where to start. Im not sure where the friction fits in.
  2. jcsd
  3. Apr 13, 2009 #2


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    Staff Emeritus
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    Homework Helper

    As written, this is what's known as an "overspecified" problem. There is actually more information given than what is required.

    Using F d cosθ, using the given 60.0 N force, will work just fine.

    Alternatively you could balance the forces to find the normal and friction forces. The friction force should balance the horizontal pull from the boy ... though they turn out to be slightly different using the numbers given here (?).
  4. Apr 13, 2009 #3
    Alright that makes scene. It worked out for me. I hate the extra stuff in problems.
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