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Determine the magnitude of the minimum acceleration

  1. Sep 20, 2013 #1
    1. The problem statement, all variables and given/known data

    A 76-kg petty thief wants to escape from a third-story jail window. Unfortunately, a makeshift rope made of sheets tied together can support a mass of only 58 kg.Determine the magnitude of the minimum acceleration at which the thief can descend using the rope.

    2. Relevant equations

    i think T-mg=ma?

    3. The attempt at a solution
    i know tension would be the upward force and mg (weight) would be the upward force correct?
     
  2. jcsd
  3. Sep 20, 2013 #2

    haruspex

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    The signs are going to depend on how you define the positive direction. Your equation is fine if the aceleration a is defined upward (so expect a negative result).
     
  4. Sep 20, 2013 #3
    would i use the mass of the man or the mass that the sheet can with stand?
     
  5. Sep 20, 2013 #4

    haruspex

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    The question is not quite right. It should say that the sheets can withstand a weight of 58g N. Mass is not force.
     
  6. Sep 20, 2013 #5

    arildno

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    What would the tension be if a man of 58 kg chose to rest from it?
     
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