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Homework Help: River Current Speed

  1. Nov 7, 2008 #1
    1. The problem statement, all variables and given/known data

    Shareen finds that when she drives her motorboat upstream she can travel with a speed of only 8m/s, while she moves with a speed of 12m/s when she heads downstream. What is the current of the river on which Shareen is traveling?

    3. The attempt at a solution

    x= current speed
    b= boat speed

    x+b= 12m/s
    b-x= 8m/s
    x+x+8= 12
    2x= 4


    Our physics class is having a debate on whether the answer is 2m/s or 4m/s and why.
  2. jcsd
  3. Nov 7, 2008 #2
    I agree with your first answer, for reasons the algebra suggests. Maybe solve for the boat speed in either case? It will likely be inconsistent at 4m/s.
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