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Homework Help: Relative Motion in Water

  1. Jul 7, 2009 #1
    1.A girl can swim 4.5m/s. If she tries to swim across a river flowing at 3.8m/s, what is her resultant velocity?

    2. cosine, sine, tangent, v=vf -v i

    3. would i just subtract 3.8m/s from 4.5m/s in order to find the velocity?
  2. jcsd
  3. Jul 7, 2009 #2
    Note, she is swimming ACROSS a river, not against the stream.
    [tex]\vec V_{12}= \vec V_1-\vec V_2[/tex]
  4. Jul 7, 2009 #3
    So you would add the two numbers rather then subtract them??
  5. Jul 7, 2009 #4
    oh oops. i meant to say that i would subtact 4.5 from 3.8 instead and it would be negative?
  6. Jul 7, 2009 #5


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    vector addition.
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