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Homework Help: Displacement vectors

  1. Sep 29, 2010 #1
    1. The problem statement, all variables and given/known data

    2. Relevant equations

    3. The attempt at a solution
    For all of the problems I am starting to do class we must use the equation above.
    I do not understand why we use i,j,k and how they are similar to x,y,z and how to use them.
    Please help! I was absent the day we learned this and it is a fast pace class and I am trying to understand this but can't seem to fully do so!
    1. The problem statement, all variables and given/known data

    2. Relevant equations

    3. The attempt at a solution
  2. jcsd
  3. Sep 29, 2010 #2


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    Gold Member

    Its sort of the same thing, but not quite: i, j, and k are unit vectors in the x ,y, and z directions. Using x, y,and z subscripts, often imply magnitudes of the component vectors in those directions. So a vector 5i + 5j has a magnitiude of 5 units in the x direction and 5 units in the y direction. If you call the vector 5x + 5y, its easy to confuse yourself, as in your other post. So don't.
  4. Oct 5, 2010 #3
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