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Homework Help: Vector force problem, stumped.

  1. Feb 9, 2012 #1
    The problem is attached.

    I am supremely stumped. First and foremost, what the heck does "horizontal forces" mean? If they are both horizontal, how is the angle between them anything but 0/180??


    The graph has a slope of 3, therefore acceleration's x component is 3. Therefore net force x-component is 5.1


    2.6cos(a) + 9.0cos(b) = 5.1

    But so what? That's all the information that the problem gives me. Granted I know that cos(a) has to be between 1 and 0 for it to be in the positive direction...

    Any hints? I really have no idea!

    Attached Files:

    Last edited: Feb 9, 2012
  2. jcsd
  3. Feb 9, 2012 #2
    Problem is attached.


    Am I reading this correctly? By F1 is in the direction of the +x axis, do they mean that as in it has no component along y? Or just that it's x component is positive?

    Arrg, this is a terribly worded question. I really want to know what two "horizontal forces" are!

    Solved, yes, they did just mean that F1 had a y component of 0. What a headache.
    Last edited: Feb 9, 2012
  4. Feb 9, 2012 #3


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    It seems clearly worded to me. Yes, it does take some thought to get some of the details straight, but I don't consider it ambiguous at all.

    As for your earlier question about horizontal forces, it's clearly worded that the xy-plane is horizontal. That gives two dimensions.
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