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Homework Help: Vector notation to find Work

  1. Nov 13, 2012 #1
    1. The problem statement, all variables and given/known data
    workVectors.png


    2. Relevant equations
    Work = F* delta x


    3. The attempt at a solution

    My thought process since the force is given in vector notations multiply the pair of i components together same applies with j and k components. However this process actually strangely does not work. And I am baffled by why a k component missing for the initial displacement.
     
  2. jcsd
  3. Nov 13, 2012 #2

    Doc Al

    User Avatar

    Staff: Mentor

    The k component happens to equal 0 at the initial position. So what?

    Figure out the displacement: r2-r1
     
  4. Nov 13, 2012 #3
    after substraction I get 5 i - 21 j + 14k.

    5i(67i) + 23j(-21j) + 55k(14k) = 335 - 483 + 770 = 622 J <- correct! =]

    thanks for the guidance, Doc Al.
     
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