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Homework Help: Pulley problem with blocks

  1. Sep 22, 2010 #1
    1. The problem statement, all variables and given/known data

    A 24 kg block with a pulley attached slides along a firctionless surface. It is connected by a massless string to a 5.3 kg block via the arrangement shown. a) Find the acceleration of the 24 kg block. b) Find the tension in the connecting string.

    2. Relevant equations

    F = ma

    3. The attempt at a solution

    For the 24 kg, I thought that 24a = 2T. Then 5.3g - T = 5.3a.
    Then set the two equal to each other, so I got a = 3.005 m/s. However, that answer is incorrect. Part b, I would just plug in the part a answer, but my part a answer is incorrect. Please help with setup, etc. Thank you!
  2. jcsd
  3. Sep 22, 2010 #2


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    Homework Helper
    Gold Member

    Hello physicsnerd11,

    Welcome to Physics Forums!
    It's difficult to give you help without a figure, diagram, or description of the system. I can only guess what the specific arrangement is.

    But I'm guessing there is some sort of pulley system involved. If so, it means that the two blocks have different velocities, and different accelerations.

    So change your equations to something like

    24a1 = 2T
    5.3g - T = 5.3a2

    giving you 2 equations and 3 unknowns. You'll need a third equation to solve this. Given the simple nature of the pulley system, what is relationship between one block's acceleration compared to the other's? :wink:
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