I know I'm making this more difficult than it needs to be. I need to find the centroid of a wire bent into the shape of a parabola, defined to be y=x^2 with -2<X>2 and 0<y>4. Obviously due to symetry X-bar =0... but what's y-bar?? No dimensions are given for the width of the wire, so I assume it is not needed. I'm guessing it has something to do with arc length... I'm still lost though. Thanks everyone.