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Homework Help: 2-D Kinematics Riverboat problem, finding current strength?

  1. Sep 18, 2010 #1

    n92

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    2-D Kinematics Riverboat problem, finding current strength??

    1. The problem statement, all variables and given/known data

    A boat whose spead is 2.20 m/s in still water must cross a 260m river and arrive at a point 110m upstream from where it starts. The boat's pilot has a heading of 45 degrees upstream, what is the current speed?

    2. Relevant equations

    sine of the angle = Vbs/Vbw ?

    Vbs - velocity of the boat relative to shore
    Vbw - velocity of the water relative to shore
    Vws - veloicty of the water relative to shore

    3. The attempt at a solution

    I'm very confused as how to tackle this problem, I started off finding the boat's velocity relative to the shore,

    2.20cos45 = 1.56 m/s

    Now that I have this I'd assume i could find the river's velocity using pathagorus, but the 45 degree angle and the fact that the boat is to travel in a line to a destination not directly in front of it has thrown me off.

    Any pointers would me much appreciated, I'm more than likely missing a crucial step that I can't see..

    Cheers.
    1. The problem statement, all variables and given/known data



    2. Relevant equations



    3. The attempt at a solution
     
  2. jcsd
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