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Homework Help: Homework Problem-Stuck?

  1. Feb 4, 2005 #1
    One afternoon, a couple walks two-thirds of the way around a circular lake, the radius of which is 1.60 km. They start at the west side of the lake and head due south to begin with.

    What are the magnitude and direction (relative to due east) of the couple's displacement?

    For the direction, is the answer found by using this: (2/3)(360 degrees) - 180?

    How would I find the magnitude?
  2. jcsd
  3. Feb 4, 2005 #2
    Well, (2/3)(360 degrees) doesn't equal 180 degrees...

    Try making a diagram. You can draw a circle on x and y axis, where the center of the circle corresponds to the origin. Place a dot on the coordinate (-1.6 km, 0), which represents the couple's initial position. If they walk 2/3 of the way, they will end up at an angle of pi/3 North of East. As for the distance, you can use simple trig.
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