Moment of inertia, often symbolized as I, quantifies an object’s resistance to rotational acceleration about a specific axis. It depends not only on the mass of the object, but also on the distribution of that mass relative to the axis of rotation. For a single point mass m at a distance r from the axis, the moment of inertia is calculated as I = mr. More complex objects require integration over the mass distribution or the application of standardized formulas based on geometry.
Understanding this rotational inertia is critical in numerous engineering and physics applications. It enables the prediction of how objects will respond to applied torques, impacting the design of rotating machinery, vehicles, and structures. Historically, the concept has evolved alongside the development of classical mechanics, offering essential insights into rotational dynamics.