Multiple$-$Concept Example $11$ provides some pertinent background for this problem. A pendulum is constructed from a thin, rigid, and uniform rod with a small sphere attached to the end opposite the pivot. This arrangement is a good approximation to a simple

pendulum $($period $=0\mathrm{.}56$ 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 no longer is a simple pendulum, but is then a physical pendulum. What is the period of the physical pendulum?