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Homework Help: Tension in a string at an angle

  1. Feb 9, 2010 #1
    1. The problem statement, all variables and given/known data
    A wire of negligible mass is used to hang a 2.15 kg picture. The ends of the wire are attached to the top 2 corners of the picture. Each end of the wire forms an angle of 15.0 degrees from the horizontal. What is the tension in the wire?



    2. Relevant equations
    [tex]\Sigma[/tex]F=ma


    3. The attempt at a solution
    This is my latest and posiibly best attmept so far, but I don't have anyone to tell me if its right or not.
    [tex]\Sigma[/tex]F+(-ma)=2Tsin[tex]\theta[/tex]-ma=0
    2Tsin15-19.737=0
    T=38.1N
     
  2. jcsd
  3. Feb 9, 2010 #2
    It's correct
     
  4. Feb 9, 2010 #3
    on which wire would you like the tension for?
     
  5. Feb 9, 2010 #4

    rock.freak667

    User Avatar
    Homework Helper

    Yes it looks correct to me.

    Though you should put ΣFy=0 when the picture is in equilibrium and then rearrange to get T.

    2Tsinθ-mg=0
     
  6. Feb 9, 2010 #5
    there is only one wire with the picture connected at the two ends hanging down.
     
  7. Feb 9, 2010 #6
    well it looks like my brilliant self put 9.18 instead of 9.81 in my calculator and subsequently got the question wrong. Man I hate online homework so much!!!!!!!!!!!!!!!!!!!
     
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