A pendulum is constructed from a thin, rigid, and uniform rod by a small sphere attached to the end opposite the pivot. This arrangement is a good approximation to a simple pendulum (period =3.72 s), because the mass of the sphere (lead) is much greater than the mass of the rod (aluminum). When the sphere is removed, the pendulum is no longer a simple pendulum, however is then a physical pendulum. What is the period of the physical pendulum?