Simple machines are mechanical devices that use levers, wheels, axles, pulleys, etc. to convert force into motion and to perform work. Flywheel Powered zeCars are perfect examples of the wheel and axle in action. Dancing Robots and Sliders include levers and rotating cams, and show the change from elastic potential into kinetic energy. Pull-Back Cars teach how torque, speed, and friction can influence the distance an object travels.