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Homework Help: Simple 3D statics problem

  1. Sep 24, 2011 #1
    1. The problem statement, all variables and given/known data
    If cable AB is subjected to a tension of 700N determine the magnitude of the vertical force F in N.

    Pic:
    [PLAIN]http://img225.imageshack.us/img225/9823/capturespm.png [Broken]


    2. Relevant equations
    Sum of forces in x y and z direction


    3. The attempt at a solution
    I am retaking my statics course after i switched majors (long story) and i kind of forgot how to solve this the RIGHT way.

    My approach would be first breaking up all the tensions in the x y and z components and summing all of those. I'll end up with 3 equations and 3 unknowns (F, AC and AD). I just feel like that's too much work...

    On top of that my book makes use of i j and k but in those problems angles are given (which does make it easier to calculate the components)

    Could someone give me a quick rundown on how to solve this?
     
    Last edited by a moderator: May 5, 2017
  2. jcsd
  3. Sep 24, 2011 #2
    Sounds like you're doing it right. You've got the forces broken down, solve for the unknowns. Make sure that you're assuming |AB| to be 700N not any one component of it.
     
  4. Sep 24, 2011 #3
    turns out working with unit vectors and i j and k is much easier! Thanks for the reply though!
     
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