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Homework Help: Finding magnitudes of vectors given angles

  1. Sep 5, 2010 #1
    1. The problem statement, all variables and given/known data

    Vector A points in the negative direction. Vector B points at an angle of 35.0 above the positive axis. Vector C has a magnitude of 16 and points in a direction 44.0 below the positive axis.
    Given that A+B+C=0 , find the magnitudes of A and B .

    2. Relevant equations

    Ax cos θ
    Ay sin θ

    3. The attempt at a solution
    I think I have the picture of the triangle graphed out, but since there are no 90 degree angles, how do I use the relevant equations to find the magnitudes?
    Last edited: Sep 5, 2010
  2. jcsd
  3. Sep 5, 2010 #2


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    Science Advisor
    Homework Helper

    That's not an equation, it's just a formula with some variables and a cosine.
    Maybe you can look up precisely what formula you wanted to write there and explain to us what it means?
    (This is not to be strict about the rules; but if you mean what I think you mean, then understanding what that formula says is the key to the solution)

    Also, can you post the complete question? You just defined A, B and C, and you have to calculate the missing magnitudes, if I understand it correctly, but that is not enough info.
  4. Sep 5, 2010 #3
    Try using the law of sines (I believe this works).
  5. Sep 21, 2010 #4
    Thanks for this, very helpful


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    Last edited by a moderator: May 4, 2017
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