A pendulum with its mass spread throughout its length is called a physical pendulum. A typical clock pendulum is an example. Students will observe a physical pendulum and measure its period, and then construct a simple pendulum with the same period. They will see that a physical pendulum acts as if its mass is concentrated at its center of mass.
![Physical Pendulum](http://www.arborsci.com/cdn/shop/articles/unnamed_b0e38b9e-8644-458a-b63e-3e85baa0c962_1100x.jpg?v=1663101958)