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Homework Help: Locate the centroid

  1. Mar 8, 2007 #1
    1. The problem statement, all variables and given/known data

    http://img170.imageshack.us/img170/214/centroidssk4.th.jpg [Broken]


    2. Relevant equations

    [tex]\bar{Y}A_{TOT}=\bar{Y_1}A_1+\bar{Y_2}A_2+\bar{Y_3}A_3[/tex]

    3. The attempt at a solution

    by observation:

    [tex]\bar{Y_1}=7.5mm[/tex]
    [tex]\bar{Y_2}=82.5mm[/tex]
    [tex]\bar{Y_3}=215mm[/tex]
    [tex]A_1=(15mm)(150mm)=2250mm^2[/tex]
    [tex]A_2=(15mm)(150mm)=2250mm^2[/tex]
    [tex]A_3=(\pi)(50mm^2)=7854mm^2[/tex]

    [tex]A_{TOT}=12354mm^2[/tex]

    [tex]\bar{Y}=\frac{1891110mm^3}{12354mm^2}[/tex]

    [tex]\bar{Y} = 153.1mm[/tex]

    The book says the answer is 154mm, I know that its not off by far but am I doing something wrong, or is the book rounding off somewhere? I am slightly off on every single question I attempt!
     
    Last edited by a moderator: May 2, 2017
  2. jcsd
  3. Mar 8, 2007 #2

    Doc Al

    User Avatar

    Staff: Mentor

    Correct this one.
     
  4. Mar 8, 2007 #3
    Righhhht, Dumb Mistake

    Thanks
     
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