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Homework Help: Forces and Newton's Laws with vectors help

  1. Jan 7, 2009 #1
    1. The problem statement, all variables and given/known data
    One force of 60N and a second of 30N act on an object at point P. Graphically add the vectors and find the magnitude of the resultant when the angle between them is as follows.

    a. 0 b. 30 c. 45 d. 60 e. 90 f. 180

    2. Relevant equations
    A-Sin A = B/Sin B = C/ Sin C
    pythagorean theorum

    3. The attempt at a solution
    I have no clue where to start
  2. jcsd
  3. Jan 7, 2009 #2


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    Homework Helper

    Welcome to PF.

    A force is a vector. [magnitude,direction]

    The question is basically asking you to add vectors.

    When 2 vectors are in the same direction then of course you just add the magnitudes and the result is the sum in the same direction.

    That's a) your 0° answer directly.

    b) asks you to add 2 vectors that are 30° to each other, so ...
  4. Jan 7, 2009 #3
    so how would i find 30 degrees, do I use the laws of sine or cosine
  5. Jan 7, 2009 #4


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    Homework Helper

    The Law of Cosines should do it.

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