In this problem,we use the result of the previous problem for the rotationalinertia of a disk to compute the rotational inertia of a uniformsolid sphere of mass M and radius R about an axis through its center. Consideran element dill of the sphere in the form of a disk of thicknessdz at a height z above the center (see Fig). (a) Expressedas a fraction of the total mass M, what is the mass dill of the element? (b) Considering the element as a disk, what is its rotational inertia dI? (c) Integrate the result of (b) over the entire sphere to find the rotational inertia of the sphere.

Simran Bhatia , 9 Years ago

Grade 11