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Help On Moments

  1. Nov 23, 2009 #1
    Hello I'm new :)
    I'm stuck on my assignment on moments.

    1. The problem statement, all variables and given/known data

    Now i have attached a copy of my assignment paper which I scanned. Here is the link


    Now the horizontal and verticle forces sum is correct. But when I try to do the sum of moments I get 50.831 Kn when the answer should be 58.513 Kn. My lecturere gave me the answers but he said you have to show your working out so that you get it yourself.

    2. Relevant equations

    Triganometry, moments.

    3. The attempt at a solution

    see given link.

  2. jcsd
  3. Nov 23, 2009 #2
    This link shows the drawing better


    I have to determine the magnitude, direction and sense of the resultant and equilibrant forces acting on the component show in figur 1 (link above) and the perpendicular distance from their line of action from point z. But im stuck on getting the total sum of forces.
  4. Nov 24, 2009 #3
    If you want me to go through the whole problem let me know..

    But the problem with your solution is with Force B.
    Under your moment column for this force you have 5.65 x 0 = 0. This is incorrect.

    The VERTICAL moment of force B IS ZERO! Since the hozitonal distance from Fb to the pivot is 0.

    The HORIZTONAL moment would be 5.65 x (Vertical Distance from Pivot which is 3) , Giving you a horizontal moment of 16.97.

    Add these all together and you have (16.97 + 30.03) + (6 + 5.472) = 58.4

    I have a hard time reading your table, and Ive never used that method, but if you dont understand my solution I'll try it your way.
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