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Homework Help: How to write unit vector

  1. Aug 8, 2008 #1
    i get that a unit vector is U/modU but how would it be writen for example 8i-4j-8k would it be simply (8i-4j-8k)/144?
     
  2. jcsd
  3. Aug 8, 2008 #2

    CompuChip

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    Notation for the normalized vector [itex]\vec u[/itex] is also [itex]\hat u[/itex]. Note, that it is [itex]\vec u / ||\vec u||[/itex] and not [itex]\vec u / || \vec u ||^2[/itex].
     
  4. Aug 8, 2008 #3
    ah sorry i ment over root 144 . apart from that is the way i wrote it fine or would i have to split it into I J and K parts?
     
  5. Aug 8, 2008 #4

    CompuChip

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    It doesn't matter;

    (8i-4j-8k)/12 = (8/12) i - (4/12) j - (8/12) k.
     
  6. Aug 8, 2008 #5

    HallsofIvy

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    Or even better (2/3)i- (1/3)j- (2/3)k :tongue2:
     
  7. Aug 8, 2008 #6

    CompuChip

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    Which is then again equivalent to
    (2i - j - 2k) / 3
    or
    2(i - 1/2 j - k) / 3

    Take your pick (or make your own :D)
     
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