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Engineering Statics (Vector Questions)

  1. Jan 30, 2014 #1
    1. The problem statement, all variables and given/known data

    Attached below

    2. Relevant equations

    I am having a problem because the solutions manual does the parallelogram method and stupid me I cannot draw the parallelogram correctly. Specifically my drawings are off a bit. and it throws me off every time. the last one I had vector (FR) completely wrong because the damn figure.

    3. The attempt at a solution

    I attempted to draw a parallelogram but i suck at it and want some advice / help. If anyone has any suggestions. I am better on doing it into components but how would you do this in components being the axis is slanted.

    Attached Files:

  2. jcsd
  3. Jan 30, 2014 #2
    They defined the axis for you in this problem, and want you to find the components of the force relative to those axis. So what you can do is find the angle the force makes with respect to the u-v axis and use trig to find the components.
  4. Jan 30, 2014 #3
    so would i be right to say the right side has a triangle with degree measures 45, 30(alt interior angles, and 105?
  5. Jan 30, 2014 #4
    If I understand you correctly, you're saying that the angle F1 makes to the v-axis is 45degrees?
  6. Jan 30, 2014 #5
    well 180 in a line.. so 180 - 105 = 75.. for the "quadrant III" lets say.. opposite is 75 total.. but you have 30 given. so that makes the extra angle left 45. so the alt interior angle tells me that there will be a 45, 30, 105 triangle
  7. Jan 30, 2014 #6
    Correct. From that you can find the angle F2 makes relative to the v-axis as well and from that you can determine the components of the force with respect to the u-v axis.
  8. Jan 30, 2014 #7

    Ok cool thanks! One last question
    ImageUploadedByPhysics Forums1391067296.376356.jpg

    The new image I attached is so blank. Would I use the same method?
  9. Jan 30, 2014 #8
    Hmm, I'm not quite sure on this one, I would say no but don't take my word for it. What I would consider though is using the parallelogram law to create a force triangle. I can't really offer any tips on it, just draw A+B, then translate them accordingly to make the parallelogram.
    Last edited: Jan 30, 2014
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