This resource from the Physics Classroom provides an animation of the motion of a pendulum. As this demonstration shows, the motion of a pendulum is a classic example of mechanical energy conservation. In addition to an animated demonstration of a pendulum’s motion, this resource includes an interactive quiz with which you can test your own understanding of this concept. Pop-up menus allow you to check your work. Also included are links to further resources, including relevant sections from The Physics Classroom tutorials.
This is a good resource to use to help identify and correct student misconceptions about energy conservation.You should encourage students to visit this site and read the information and play with the animation. It would be a good accompaniment to a classroom demonstration of an actual pendulum.