First Moment of Area

First moment of area, abbreviated as Q, also called first moment of inertia, is the measurement of a shape's area cross-section relative to an axis, located in space.  In practical terms and of relavance to this site, the shape is generally a beam or piece of pipe.  It is the resistance of an object to bend around a certain axis.  It can be used to determine the location of the centroid, which is the point where the sum of all moments of inertia are equal.