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Homework Help: Given the diagram, what is the tension in each string?

  1. Oct 31, 2011 #1
    1. The problem statement, all variables and given/known data


    Given this diagram and the masses involved, what is the Tension in each string. All masses are 1kg.

    Diagram provided

    4.jpg

    Sorry, the angle for T2 is 10°


    2. Relevant equations



    3. The attempt at a solution

    I really don't know where to start.
     
    Last edited: Nov 1, 2011
  2. jcsd
  3. Oct 31, 2011 #2

    Redbelly98

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    For each mass, draw a force diagram.

    Then use ∑Fx=max and ∑Fy=may. (And you should know what ax and ay are :wink:)
     
  4. Oct 31, 2011 #3
    okay, so for T1 and T2..

    x-dir would be ∑Fx = - T1 cos30 + T2 cos10 = 0

    y-dir would be ∑Fy = T1 cos30 + T2 cos10 + -mg = 0

    Then solve for T1 = T2 cos10/cos30 = 0

    Plug into y-dir eq. (T2 cos10/cos30) cos30 + T2 cos10 = mg

    T2 = mg/1.97 which is 4.97.

    Then plug T2 to T1. Correct?

    Now I am uncertain about T3 and T4..
     
    Last edited: Oct 31, 2011
  5. Nov 1, 2011 #4

    Redbelly98

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    Yes, good.
    Almost -- for the y-dir, we use sin instead of cos.
    Except for the "=0" part, that is correct.
    Yes, except that there should be some sin's in there because of what I said before about the y-direction forces.
    Yes, that is the idea.
    Have a look at the forces acting on Mass #3.
     
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