# structural mehanics help needed!! - centre of gravity

• Dec 2nd 2008, 07:58 AM
bandy1989
structural mehanics help needed!! - centre of gravity
please could i have help with the question attatched
it is about centre of gravity.
thanks
• Dec 2nd 2008, 08:19 AM
vincisonfire
Cut your figure into two pieces. (a square and a triangle)
You can easily find the coordinates of the center of mass of the square using symmetry arguments.
You can find the coordinates of the center of mass of the triangle using the definition of the mean
$c_x=\frac{\int x f(x) dx}{\int f(x) dx}$
$c_y=\frac{\int y f(y) dy}{\int f(y) dy}$
Then you can find the center of mass of the whole thing with
$*MR = m_1r_1+m_2r_2$*r being the vectors of position.
• Dec 2nd 2008, 08:21 AM
bandy1989
thanks
thanks alot thats a big help.