To finalize this problem, note that the initial configuration
in this example is the same as that in Example 10.10. In Example 10.10, however, we could only find the initial angular
acceleration of the rod. We cannot use this and the kinematic equations to find the angular speed of the rod at its
lowest point because the angular acceleration is not constant. Applying an energy approach in the current example
allows us to find something that we cannot in Example 10.10.