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Homework Help: What is the magnitude of the sum of the following vectors?

  1. Jan 15, 2012 #1
    1. The problem statement, all variables and given/known data

    What is the magnitude of the sum of the following vectors?

    A= i +5j -k

    B= 4i-j-5k

    C= -i+j


    2. Relevant equations




    3. The attempt at a solution

    What I did was I added i+4i-i to get 5i, I also added 5k+j-5 to get 5j, likewise for k to get -6k

    and did the squareroot of (25+25+36) to get squareroot of 86 or 9.27 however that is not the right answer. What am I doing wrong?

    Thank you
     
  2. jcsd
  3. Jan 15, 2012 #2

    Doc Al

    User Avatar

    Staff: Mentor

    Redo that addition.
     
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