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Homework Help: Worker pushes a box

  1. Oct 27, 2008 #1
    1. The problem statement, all variables and given/known data
    On a horizontal frictionless floor, a worker of weight 900N pushes horizontally with a force of 200N on a box weighing 1800N


    2. Relevant equations



    3. The attempt at a solution
    I do not know where to start.
     
  2. jcsd
  3. Oct 27, 2008 #2

    PhanthomJay

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    What's the question?
     
  4. Oct 27, 2008 #3
    As a result of the push:
    A. the worker and box will both have an acceleration of 2.18m/s^2, but in opposite directions
    B. The worker will accelerate at 1.09m/s^2 and the box will accelerate at 2.18m/s^2, but in opposite directions
    C. The worker will accelerate at 2.18m/s^2 and the box will accelerate at 1.09m/s^2, but in opposite directions
    D. The worker and box will both have an acceleration of 1.09m/s^2, but in opposite directions
    E. The box will not move because the push is less than its weight
     
  5. Oct 27, 2008 #4

    PhanthomJay

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    What have you tried so far?
     
  6. Oct 27, 2008 #5
    well i think the sum of the forces in the x direction must equal ma
    Fx=ma
    200N= ((1800N+900N)/9.81)*a
    But this can't be right because the value for a doesn't fit the answers
     
  7. Oct 27, 2008 #6

    HallsofIvy

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    Do you mean "which of these is true"? Is so, it would have helped a lot if you had said that in your first post!

    I don't see any need to do ANY calculation. One answer can be thrown out because it is just silly. The correct choice from the other 4 only requires recognizing that the worker has greater mass than the box!
     
  8. Oct 27, 2008 #7
    the worker has a mass of 900N the box has a mass of 1800N
    1800>900
     
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