Second moment of area
The moment of force (also called the first moment of force) about any point is the product of the force and perpendicular distance between them. If this first moment is again multiplied by the perpendicular distance between them, the product so obtained is called the second moment of force or moment of moment of the force.
If instead of force, the area of the figure or mass of the body is considered, it is called the second moment of area or second moment of mass. They are also termed broadly as moments of inertia.
There is no physical significance for moment of inertia. It is just a mathematical expression usually denoted by [math]\displaystyle{ I }[/math]
Second Moment Of Area Media
An arbitrary shape. ρ is the distance to the element dA, with projections x and y on the x and y axes.
A shape with centroidal axis x. The parallel axis theorem can be used to obtain the second moment of area with respect to the x' axis.
Rectangle with base b and height h
Annulus with inner radius r1 and outer radius r2
A simple polygon. Here, n=6, notice point "7" is identical to point 1.
