This editor-recommended, interactive tutorial covers the basics of energy in the context of introductory physics. This is the second of five pages discussing the concept and mathematics of mechanical energy. The author presents Work and Energy as a means to analyze the motion of objects, an area of demonstrated weakness among secondary students. Detailed explanations and sample problems allow students to explore potential, kinetic, and mechanical energy, while also introducing related equations. Included are force diagrams, quick links to pertinent definitions, and links to animations that allow learners to visualize what is being discussed.