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Homework Help: Just some language

  1. Sep 29, 2004 #1

    Alkatran

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    Which statements are true?

    A) A vector can have zero magnitude if one of its components is not zero.
    B) If a + b = c and a2 + b2 = c2, then the angle between a and b is 90°.
    C) Two vectors having different magnitudes can be combined to give a vector sum of zero.
    D) The magnitude of the difference between two vectors can be greater than the magnitude of at least one of the vectors.
    E) If a + b = c and a2 + b2 < c2, then the angle between a and b is between 0° and 90°.
    F) Three vectors which do not lie in the same plane can never give a vector sum of zero.
    G) If a + b = c and a + b = c, then the angle between a and b is 180°.


    I've got: FTFTTTF

    I just need some help translating what these questions mean
    A: Components are the x,y,z components. Magnitude has to be > 0
    B: Is it a length or a vector? I know that since they're perpendicular two vectors squared WILL equal...
    C: Obviously if one is shorter than the other it can't undo the other completely
    D: Opposite directions. True
    E: I'm not sure. But I think this is true... unless than angle can be greater than 90?
    F: True
    G: In the question the first a + b = c is bold and the second is italics, that's the only difference between them. I highly doubt it change their meaning, other than that I think G is false.
     
  2. jcsd
  3. Sep 29, 2004 #2

    Alkatran

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    Got it.

    Why can't I delete the post?
     
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