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Very basic motion law - newton's 2nd

  1. Sep 22, 2008 #1
    1. The problem statement, all variables and given/known data

    a 5 kg object placed on a frictionless, horizontal table is connected to a string that passes over a pulley and then is fastened to a hanging 9 kg object. Find the acceleration of the two objects and the tension in the string.

    2. Relevant equations

    F = ma

    3. The attempt at a solution

    It just seems to me that if there is no friction the second object on the horizontal table should travel as the same speed that the 9.00 kg object falls. If there is no friction, then I don't see what force would be needed to "pull" the second object across the table, or how it would slow down the 9 kg object.

    Thank you!
  2. jcsd
  3. Sep 22, 2008 #2


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    Homework Helper

    Draw a diagram. If there is tension in the line then whatever force there is from gravity on the hanging weight will be used to accelerate both weights.
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