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Homework Help: 3 Pulley System

  1. Dec 5, 2008 #1
    1. The problem statement, all variables and given/known data

    Three objects m1. m2 and m3 are suspended from three massless and frictionless pulleys as
    shown in the diagram. m1 is 6 kg, m2 is 2 kg and m3 is 3 kg. Find the tension of the string
    when the system is set in motion (i.e. all masses are moving). Answer in N.

    2. Relevant equations

    3. The attempt at a solution
    I've got all the f=ma equations set up, but cannot figure out how to relate the accelerations to one another. I tried a1=a3=-2(a2) but that did not give me the correct answer. hopefully someone can help me with this.


    Attached Files:

  2. jcsd
  3. Dec 5, 2008 #2


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    Gold Member

    I can't see yet the picture but take note that the acceleration of each block must be the same.
  4. Dec 5, 2008 #3


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    Homework Helper

    Net downward forces due to 3 kg and 6 kg must be equal to net upward force on 2 kg.
    Now try to find the tension.
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