Somehow, when I am teaching Physics, I feel like I am holding out on my students until we get to work and energy. Once we start problem solving using energy rather than dynamics, there is a certain elegance, and a much greater portability – principles of energy are quite general, and can be applied outside the Physics classroom much more readily than, say, Newton’s Laws. Central to using W&E are the law of conservation of energy and the Work-Energy theorem. In order to illustrate the law of conservation of energy in class today we took a video of a pendulum and dropped it into Tracker. Here is the result:
I love the way this came out, showing the kinetic and potential energies swapping back and forth. This was a very easy, and very visual demonstration.