Rotational inertia, also known as moment of inertia, is a measure of an object's resistance to changes in its rotational motion. It depends on the mass distribution and shape of an object.
Rotational inertia is calculated by multiplying the mass of an object by the square of its distance from the axis of rotation. It is represented by the symbol I and has units of kilogram-meter squared (kg·m²).
The factors that affect rotational inertia are the mass of the object, the distance of the mass from the axis of rotation, and the shape of the object. Objects with larger masses and farther distances from the axis of rotation have a higher rotational inertia.
Rotational inertia is important because it helps us understand how objects move and behave when rotating. It is also essential in many practical applications, such as designing machines and calculating the stability of structures.
Rotational inertia and linear inertia are both measures of an object's resistance to change in motion. However, rotational inertia applies to objects rotating around an axis, while linear inertia applies to objects moving in a straight line. Additionally, rotational inertia depends on the object's shape, while linear inertia does not.