Rotational Inertia

Definition

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 both the mass and distribution of mass around the axis of rotation.

Analogy

Think of rotational inertia like a spinning top. The more mass it has concentrated towards its edges, the harder it is to change its spinning motion. Similarly, objects with greater rotational inertia are more resistant to changes in their rotation.

Related terms

Torque: Torque is the measure of how effectively a force can cause an object to rotate. It depends on both the magnitude and direction of the force applied.

Angular momentum: Angular momentum is a property that describes an object's tendency to keep rotating at a constant rate. It depends on both rotational inertia and angular velocity.

Center of mass: The center of mass is the point where all the mass of an object can be considered to be concentrated. It plays a crucial role in determining an object's rotational behavior.