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Homework Help: Subtracting 3 Vectors

  1. Nov 5, 2009 #1
    If A= 60.0 and theda = 56.5 degrees
    of this graph
    http://www.flickr.com/photos/44447874@N08/4079278252/ [Broken]

    can you help me find C - A - B?
    magnitude and direction (counterclockwise from the +x axis is positive)

    Also how do I find 2A - 3B + 2C?

    Thank you
    Last edited by a moderator: May 4, 2017
  2. jcsd
  3. Nov 5, 2009 #2

    Andrew Mason

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    Science Advisor
    Homework Helper

    Vector subtraction A = C-B can be remembered this way: Ask yourself: what vector A added to B results in C? This is equivalent to switching the head and tail in B (ie multiplying it by -1) and adding it to C.

    C - A - B = C + (-A) + (-B)

    To add vectors simply add their respective x components to get the x component of the resultant and add the y components to get the y component of the resultant.

    So add the x component of C to -1* the x component of A and add -1* the x component of B. Then to the y component of C add -1* the y component of A + -1* y component of B.

    Last edited by a moderator: Apr 24, 2017
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