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Homework Help: Compound pendulum

  1. Apr 21, 2012 #1
    Little help in compound pendulum

    1. The problem statement, all variables and given/known data
    there is an equilateral triangle T with sides of length B. Suspend this triangle from a pivot throught on of its corners, so that it is free to swing about this corner in the plane of the tringle.

    I want to ask how to compute the density p(x,y) and the R whcih from the pivot point to the center of gravity of the triangle.

    In fact I found the soluation, but I don't know it is right or not.
    Could anyone check it with me?

    2. Relevant equations
    p(x,y)=m/A


    3. The attempt at a solution
    A=sqrt(3)/4 * B^2
    therefore p(x,y)=(4*sqrt(3)*m)/(3*B^2)

    about the R:
    GRAPH.jpg
    cos 30 = sqrt(3)/2
    R = (B/2)*(2/sqrt(3)) = (sqrt(3)*B)/3

    did I make any mistake??

    Thanks a lot
     
    Last edited: Apr 21, 2012
  2. jcsd
  3. Apr 21, 2012 #2
    You did not.
     
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