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Vectors -- Adding velocity vectors to make a resultant

  1. Aug 26, 2014 #1
    1. The problem statement, all variables and given/known data

    Determine the vectors A-C, given the vectors A and C in Fig. 3-32. Vector A=44.0 at 28 degrees north of east and vector C=31.0 at 90 degrees south of east.

    2. Relevant equations
    I don't know any.

    3. The attempt at a solution
    44.0-31.0=11.0, 28.0-90= -62
    The answers are 64.6 and 53.1 degrees.
  2. jcsd
  3. Aug 26, 2014 #2


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    Gold Member

    Hmmm... you took 2 vector lengths, and subtracted them. That works if they're parallel, but not at different angles.

    Write your vectors in a couple different forms and post back. (I'm sure you've seen different ways to express the same vectors)
  4. Aug 27, 2014 #3


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    Staff: Mentor

    We don't see Fig. 3-32, but I assume you do.

    First step, sketch the vectors in their given orientation so you can see what you are dealing with.

    Second step, remember the rule that says to subtract a vector you can reverse its direction and add it.

    BTW, you might need to brush up on your arithmetic, too. :wink:
  5. Aug 27, 2014 #4


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    Staff: Mentor

    It's unusual and longwinded to describe a direction as 90 degrees South of East. Are you sure you have that specification correct?
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