In the imperial system, the unit is inches to the fourth power (in 4). The SI unit of the polar moment of inertia is metered to the fourth power (m 4). Where, r = distance to the element dA Units Polar moment of inertia can be mathematically represented by the given formula Polar moment of inertia is also known as second polar moment of area. Polar moment of inertia describes the cylindrical object’s resistance to torsional deformation when torque is applied in a plane that is parallel to the cross section area or in a plane that is perpendicular to the object’s central axis.

Polar moment of inertia is a quantity used to predict an object’s ability to resist torsion, in objects ( or segments of objects) with an invariant circular cross section.

The mass remains same and its radius is larger compare to above disc. Now, melt this disc and convert it into ring which is shown in figure Example (2) Consider a disc of radius R and mass M. If you rotate baseball by holding the handle, you have to put in more effort than when you rotate baseball by holding it at its hitting end. If the greater mass is concentrated away from the axis, then moment of inertia will be greater.įor example(1), take a baseball club. Physical significance of moment of inertia hence moment of inertia about the X-axis is represented by Iₓₓ whereas about Y-axis represents Iyy. of the area ( or mass ) from an axis is called the moment of inertia of the area ( or mass ) about that axis. The product of the area ( or mass ) and the square of the distance of the C.

Moment of inertia formula Moment of inertia definition Let’s see what are they:- Moment of inertia formula Moment of inertia formula So, I have given some formula for the moment of inertia of different objects having a different geometrical shape. It depends on geometrical shape of the object like a circular, rectangular, triangular, thin rod, etc. The formula for the moment of inertia is different for different shapes of the object. Numerical to calculate Moment of Inertia The formula for moment of inertia.Example (2) Consider a disc of radius R and mass M.Physical significance of moment of inertia.

Mass moment of inertia of a circle