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Homework Help: Velocity as a Vector

  1. May 5, 2008 #1
    1. A light plane is traveling at 175 km/h on a heading of N 8 degrees E in a 40km/h wind from N 80 degrees E. Determine the plane's ground velocity.

    2. Relevant equations

    3. The attempt at a solution
    Im having problems drawing the vector, i am not to sure at how it looks. if someone could help me draw it, and just a brief outline on how to solve the question.
  2. jcsd
  3. May 5, 2008 #2
    So your plain is going almost straight "up", and slightly to the right. The wind is blowing down and left, mostly left (wind is FROM N by E, not blowing to there).

    So you should draw Line 1 going from your origin, mostly up and slightly to the right. Line 2 starts at the end of Line 1, is shorter than Line 1 (about 1/4th as long), and is going mostly to the left, slightly down. Then connect the origin with the end of Line 2.
  4. May 6, 2008 #3


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    Welcome to PF!

    Hi victoria! Welcome to PF! :smile:

    Think of it like a river … you point the boat in a particular compass direction, but when you get to the other side you find that the flow of the river has carried you downstream.

    The first side of the triangle is your velocity relative to the water, the second side is the velocity of the water! :smile:

    (oh … and always draw little arrows on the sides of your triangles! :smile:)
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