![area moment of inertia of a circle x axis area moment of inertia of a circle x axis](https://pressbooks.bccampus.ca/universityphysicssandbox/wp-content/uploads/sites/287/2017/11/CNX_UPhysics_10_04_RotInertia.jpg)
The centroid of an area,, is called the first moment of area. The moment of inertia is also called the second moment of area. 10.1 Terms involved in calculating the moment of inertia of an area about an axis m. This quantity has the dimension of the length to the power of four (e.g. The value of depends on the location and direction of the axis, and the shape of the area. The differential element,, in this definition, is infinitesimal (approaching to zero) in any directions on the plane.
![area moment of inertia of a circle x axis area moment of inertia of a circle x axis](https://mathalino.com/sites/default/files/reviewer-mechanics/821-rectangle-minus-semi-circle-composite.gif)
Where is the moment of inertia of the area about an axis in the plane of the area, and is the perpendicular distance from the axis m to the differential area as shown in Fig.
![area moment of inertia of a circle x axis area moment of inertia of a circle x axis](https://www.efunda.com/math/areas/images/CircleHalf0.gif)
The mathematical definition of the moment of inertial of an area (two-dimensional region) about an axis is, stiffness) is against bending or twisting about some axis. Its value reflects how strong an object (i.e. The moment of inertia of an area is a geometric property of the area. The moment of inertia of an area about an axis is a concept appearing in the formulations of several physical phenomena. Open Educational Resources Moments of Inertia of area: