A conceptual statement made by the parallel axis theorem is one that you probably could have arrived at by means of common sense, namely that the moment of inertia of an object with respect to an axis through the center of mass is smaller than the moment of inertia about any axis parallel to that one. Learn what is parallel axis theorem , how to derive it, and how to apply it to calculate the moment of inertia of a body. Also, find out the perpendicular axis theorem and its applications in physics. These theorems help students calculate the moment of inertia of various bodies about different axes with ease. They are especially useful when direct computation is complex or not practical. Understanding these theorems allows you to solve many numerical and conceptual problems in rotational dynamics confidently. Learn how to calculate the moment of inertia of a rigid body about any parallel axis using the parallel axis theorem . See the formula, derivation, and examples for different shapes such as rod, ring, disc, and sphere.
