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Homework Help: Resolution of forces(tension force)

  1. Oct 25, 2006 #1
    View attachment Forces.doc

    The two diagrams show a load hanging with View attachment Forces.doc 2 strings of the same size and type hanging from a flat plane.
    Find the tention on each string for both situations.

    I know that

    Fy of both strings in Diagram 1 are equal.

    Thus the
    Fy=10 N

    However, for the situation in the Diagram 2, I am not sure whether
    Fy1 =Fy2
    So, are both of the vertical components of both the strings at different angles equal?

    ~sorry I couldn't add a bmp file.~
  2. jcsd
  3. Oct 25, 2006 #2

    Andrew Mason

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    You can answer this question yourself if you do a free body diagram showing all the Force vectors acting and do the analysis. But you can also just think about it a bit. Suppose you have a mass held by one string, vertically. Then you attach a second string from a long horizontal distance away to the mass and pull the mass a little horizontally. Are both strings providing the same vertical force?

    Do the analysis:

    You have the vertical components of the tension in each string acting up and mg acting down. What can you say about the sum of those forces?

    You also have the horizontal components of the tensions acting in opposite horizontal directions. What can you say about the sum of those forces?

    Now you have two equations with two unknowns (T1 and T2). You can solve for T1 and T2. You can work out the vertical components and see how they compare.

  4. Oct 26, 2006 #3
    I still don't get it.

    But correct me if I'm wrong,

    the vertical component is not distributed equally to bothe strings in the 2nd diagram.
    Thus, each string at different angles from the wall possess different magnitude for its vertical component(Fy).
  5. Oct 26, 2006 #4


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    That is correct, but it does not tell you how to divide the force between the two vertical tension components. You have to look elsewhere for the information to figure that out. The elsewhere is included in AM's post. What other tension components have you not yet considered?
  6. Oct 26, 2006 #5
    Thanks for the tips and info AM n OD!

    i shall work it out n present my results n workings , yeah!

    You both have been great help since i got in to PF!
    TY for that.
    Last edited: Oct 26, 2006
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