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Homework Help: Work on sliding bag on aircraft

  1. Nov 3, 2005 #1
    Can anyone help me with this problem?

    A flight attendant pulls her 70.0 N flight bag a distance of 258 m along a level airport floor at a constant speed. The force she exerts is 32.0 N at an angle of 52.0° above the horizontal. Find the work she does on the flight bag and the work done by the force of friction of the flight bag.

    I was able to make a free body diagram and see that the weight of the flight bag is 70 newtons, the displacement is 258 m. But when I solved for W, which is force x displacement x cosine 52 degrees I got the wrong answer.
    (70 x 258 x cos52).
     
  2. jcsd
  3. Nov 3, 2005 #2
    your answer looks right to me, why do you say that it is wrong.

    1345.65J
     
  4. Nov 3, 2005 #3

    verty

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    Isn't the calculation 32*cos52*258? Since the speed was constant, friction did the same amount of work.
     
  5. Nov 4, 2005 #4
    Online

    Because the assignment is online, I'm able to put it in to see if I get it right or not.
     
  6. Nov 4, 2005 #5

    lightgrav

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    The 70 N weight has nothing to do withthe flight attendant's Work;
    most of it is cancelled by the Surface compression Force by the Floor (F_N).
    vertigo is right, there.
    But Friction did a NEGATIVE amount of Work
    (total external Work done on the bag = change of its KE = 0).
     
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