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Vector problem

  1. Sep 2, 2007 #1
    In the sum A + B = C, vector A has a magnitude of 10.1 m and is angled 46.0° counterclockwise from the +x direction, and vector C has a magnitude of 16.8 m and is angled 17.7° counterclockwise from the -x direction. What are (a) the magnitude and (b) the angle (relative to +x) of B? State your angle as a positive number.

    Some help here please
  2. jcsd
  3. Sep 2, 2007 #2


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    Homework Helper

    Did you draw it out? What is giving you trouble? You need to show some of your thoughts.
  4. Sep 2, 2007 #3
    Yes, try drawing it out and filling in all the details regarding the angles and magnitudes. It should be much easier to see what needs to be done.
  5. Sep 2, 2007 #4
    Yea I am knd of stuck on it I believe you have to find the magnitude by using the pythagorean theorem but calculating the angle is what is giving me trouble
  6. Sep 2, 2007 #5
    Keep in mind that B = C + (-A) so you can draw C and -A (same as A except in the opposite direction, watch your angles!), and then since you know the angles and the magnitudes of these vectors you can get the x- and y-components and find the components of B. The angle will follow from this once you know it, as well as the magnitude.

    Keep at it.
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