## Physics for Scientists and Engineers: A Strategic Approach with Modern Physics (4th Edition)

We can use the equation for the period of a physical pendulum: $T = 2\pi~\sqrt{\frac{I}{mgd}}$ $I$ is the moment of inertia $d$ is the distance from the center of mass to the pivot The mass and distance to the pivot are the same for both objects. However, the hoop has a greater moment of inertia than the disk. Therefore, the hoop has a larger period of oscillation.