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Homework Help: Finding the forces of a beam

  1. Sep 26, 2013 #1
    1. The problem statement, all variables and given/known data

    Hi. Question 1-5 from http://www.slideshare.net/hotman1991/met-302-chapter-01 has me puzzled. In the support reactions in Fy, they state By + 3.00 - 9.00 = 0. I do not understand why the 3 is positive.

    2. Relevant equations

    3. The attempt at a solution

    When doing it myself, I took point A as the Pivot point. So I have negative 9 kip (from that 0 to 1.5 kip triangle), By, and *negative* 3 kip from the force right beside E. Is there something wrong with my logic?
  2. jcsd
  3. Sep 26, 2013 #2


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    The +3 kip load is the reaction at point A. The load of -9 kips comes from the triangular load between points A and B. Remember, the point of this exercise is to find the internal loading of the beam at point B.
  4. Sep 26, 2013 #3
    Wow. Cannot believe I messed that up. Crystal clear now, thanks.
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