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Homework Help: Relative vectors problem

  1. Sep 22, 2008 #1
    I found the answer for the first part of the problem to be 10 units. But I have no clue how to deal with the second part :) Please give some hints how to solve this following prob.

    1. The problem statement, all variables and given/known data
    Two vector A and B, are drawn on an x-y coordinate system as shown. Vector A has a magnitude of 8 units, and vector B has a magnitude of 6 units. Find the x- and the y- components of vector A and B in the x-y system. Compute the magnitude of the resultant in the x-y coordinate system. A second coordinate system, the x'-y' system , is rotated 37 degree with respect to the x-y system as shown. Find the x'- and y'- components of A and B in the x'-y' system. Compute the magnitude of the resultant vector in the x'-y' coordinate system.


    2. Relevant equations
    no clue :(

    3. The attempt at a solution
    Don't know!
  2. jcsd
  3. Sep 22, 2008 #2


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    Homework Helper

    You have the magnitude, but how would you write the vectors in the x-y?

    For instance A = 8 * x-hat + 0 * y-hat
    Now write B.

    For the x'-y' translation you simply state these vectors in their components at the appropriate angles to the new axes.
  4. Sep 22, 2008 #3
    Aha ;)) Great thank to you! I'll try it now.
  5. Sep 23, 2008 #4
    So, I have the result:

    Ax'= 8cos37x'-hat= (6.4x'-hat)
    Ay'= -8sin37y'-hat = -4.8y'-hat

    Bx'= 6cos37x'-hat= 4.8x'-hat
    By'= 6sin37y'-hat = 3.6y'-hat

    Is it right?
  6. Sep 23, 2008 #5


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    Homework Helper

    That looks right. I would express it as the sum of the x and y components though.
  7. Sep 23, 2008 #6
    ;)) Thanks alot, LowlyPion for your helpfulness and kindness.
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