Help with centre of mass please

[dirac1]

http://i3.tinypic.com/wmjdqh.jpg

its question number 10

hi all i was wondering if you could help me with my centre off mass question sthanks

the diagram shows a thing uniform sqaure of metal which has a corner folded over. Calculate the distance the centre of mass of ABCDEF is from A

thanks you

 

[berkeman]

So what techniques do you use to calculate the center of mass of an object? You need to show us how you are starting to solve the problem...

 

[dirac1]

i used or tried centr mass of triangle =1/3 height and 1/3 width i then used centre mass of square is 1/2 base and 1/2 height.

i then took the triangle away from the sqaure a little like this

centre of mass of triangle
x=4+4/3=5 and 1/3
y=4+4/3=5 and 1/3

centre of mass of sqaure =
x=4
y=4

mass of square - 8x8=64
mass of triangle - 4x4=16

i tried distance between two points is [(x1-x2)^2+(y1-y2)^2)]^0.5

but it didnt work :(

just wondered where I am going wrong

 

[Hootenanny]

You may want to check the x distance for your COM of the triangle. And also the mass of your triangle.

~H

 

[dirac1]

thyanks buddy i got it now