This simulation-based learning module for Grades 6-8 was developed to help students visualize changing kinetic and potential energy in a simple pendulum. It models a child on a swing suspended from a stationary point. Drag the swing to different heights, then activate the motion. As the swing moves in periodic motion, energy bar graphs are simultaneously displayed that show changing kinetic and potential energy. A third graph of TME (total mechanical energy) clearly shows that the total energy of the system is conserved, even though kinetic and potential energies are continuously changing. The “Supplemental Document” contains two problem sets designed specifically to accompany the simulation: 1) Conceptual activity with only energy data to explore transformation and conservation of energy, and 2) Quantitative activity that incorporates height and speed data for calculating the mass of the figure on the swing. Tables are provided for recording data. Complete answer key makes this a classroom-ready resource.