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Homework Help: Trigonometry and Physics?

  1. Jun 11, 2009 #1
    1. The problem statement, all variables and given/known data

    Bob heads out into a lake at an angle of 36 degrees, with respect to the shore. If his boat is capable of a speed of 1.7 m/s, how far from land will he be in 7 min and 23 s? Answer in units of m.

    2. Relevant equations

    I have no idea what equation would work for this. It was about to apply projectile motion but "g" does not apply to this, and equations for projectile motion involve "g" ...

    3. The attempt at a solution

    All I've figured out in the past two hours is that 7 min and 23 s = 443 seconds.

  2. jcsd
  3. Jun 11, 2009 #2


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    How many meters is that?

    Now that you have distance, don't you have a hypotenuse?

    If you have the angle, then what trig function times the hypotenuse will yield your distance perpendicular from the shore?
  4. Jun 11, 2009 #3

    How many meters is what?

    I don't have a distance.

    I was thinking inverse cos of 36 degrees. That would give me the hypotenuse right?
  5. Jun 11, 2009 #4


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    You have the time. You have the velocity.

    Why don't you have the distance traveled?
  6. Jun 12, 2009 #5
    This is a trig problem. Make a diagram, the boat leaves the shore at an angle. Distance traveled equals rate X time, you have both as pointed out by Lowlypion. Use the appropriate trig function to solve for the distance the boat is from the shore after 443 seconds.
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