1. The problem statement, all variables and given/known data Find the Y component of the Center of Mass http://img607.imageshack.us/img607/7122/83370796.png [Broken] 2. Relevant equations ∫(r*dm)/M 3. The attempt at a solution I keep coming up with (2/3)B but i know since that there is more mass near the origin axis, it should be 1/3B. I think it is my definition of area that is wrong. I am using horizontal strips with A * dy but i am unsure how to substitute A since it is a varying as y increases ∫(r*dm)/M σ=dm/da σ*da=dm ∫(r*σ*da)/M da= area of small strip = dy*Mslope= Y=Mslope*x= Mslope=B/A ∫(y*σ*dy*y(A/B))/M y(A/B)=X (σA/BM )∫y^2dy= σ= M/Area Area = 1/2AB σAB=2M (AσB2/3M)= (σAB/3M)*B = (2MB/3M)= (2/3)B Which is wrong. I think the error is somewhere around the da part. I am a little bit unsure of what the area of each horizontal strip would be since the left side of the shape is a function of x, or is it a function of y?