1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Determining the forces in three cables.

  1. Mar 11, 2015 #1
    1. The problem statement, all variables and given/known data

    2. Relevant equations

    3. The attempt at a solution
    1. I first found the angles each cable made with the pillar.
    2. With these angles I found the components of the forces in the x and y direction.
    3. So ∑Fx and ∑Fy were found.
    4. Then using these values I equated that
    ## F = \sqrt(F_x ^2 + F_y ^2) ##
    5. The from here I subbed Fb and Fc = Fa and that F = 200kN Then rearranging to get Fa I got Fa = 112.36N however it should be 68.4kN.

    I am unsure where I have gone wrong. Note vectors are not to be used to solve problem i.e using i, j and k components.

    Attached Files:

  2. jcsd
  3. Mar 11, 2015 #2


    User Avatar
    Homework Helper
    Gold Member
    2017 Award

    Your approach looks good. You must be making an error somewhere in the calculation. I get 68.2 kN for the answer.
  4. Mar 11, 2015 #3
    So could you give me a rough outline of your method.
  5. Mar 11, 2015 #4
    Don't worry I worked it out.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted