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Find the angle the boat has to head

  1. Oct 19, 2011 #1
    1. The problem statement, all variables and given/known data
    A boat, which can travel at 8.2 m/s in still water, heads directly across a river which has a current of 4.5 m/s and is 477 meters wide. What should the heading of the boat be in order for it to land at a point on the opposite shore exactly 100 m upstream from the starting point?

    2. Relevant equations
    Not sure

    3. The attempt at a solution
    I really don't know where to start
    Thanks for the help!
  2. jcsd
  3. Oct 20, 2011 #2
    I'd think of it as a triangle. You have the speed across (8.2 m/s), the base 477 m and the speed along the short side 4.5 m/s. That's the geometry answer, but it's simple.
    Of course, in the real world you just keep adjusting the boat to get to the point you want to go. You start off, realize your going down stream, and adjust your angle upstream to compensate. You change your speed a lot too, but that's the real world of boats.
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