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Homework Help: Value of an angle will their vector sum have the same magnitude

  1. Sep 4, 2004 #1


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    i'm stumped totally on this physics question. help please?

    vectors a and b are drawn from the same origin with an angle seperating the two vectors. if a and b have the same magnitude, what value of an angle will their vector sum have the same magnitude as vectors a or b?

    i've tried over and over to figure this out..but, im stumped, maybe im approaching it the wrong way or something.
  2. jcsd
  3. Sep 4, 2004 #2

    Chi Meson

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    It's easier to figure this out graphically (rather than mathematically). Have you done "the parallelogram method" of vector addition? If you have, then scribble around a bit on some paper:

    Draw two equally long vectors at various angles from each other (acute and obtuse), then draw in the resultants. When you get close to having a resultant with the same length as the two componants, you ought to be able to recognize a certain kind of triangle in your drawing.

    PS. Further questions like this should be posted in the Homework Help forum, which is way down near the bottom of the main menu.
  4. Sep 4, 2004 #3


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    oh sorry, didnt see the homework part. thanks thanks
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