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Homework Help: Work done tow truck

  1. Mar 31, 2010 #1
    1. The problem statement, all variables and given/known data
    A tow truck drags a stalled car along a road. The chain makes an angle of 30 deg with the road and the tension in the chain is 1500 N. How much work is done by the truck in pulling the car 1 km?

    2. Relevant equations

    3. The attempt at a solution
    What I'm confused about is whether we use W = FD or W=FDcos30
    What I did was find the horizontal component of force (though I don't know if we use this or the tension given) F = 1500cos30=750*sqrt(3)
    then i did W = FDcos30 = 750*sqrt(3)(1000)(cos30) = 1125000

    Do i even put cosine again to find work?
    Or can i just do W=FD
    W=750*sqrt(3)(1000) = 1299038
  2. jcsd
  3. Mar 31, 2010 #2


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    Homework Helper

    No the component of the force in the direction of motion is Fcosθ, so the work done is W=(Fcosθ)d, which is what you first did.
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