Using the air track, two carts are attached to each other with a spring that can expand and compress. When you push the system, the carts oscillate around the center of mass, which moves in a straight path. The system eventually comes to a stop as the spring dampens the system's kinetic energy.

Carts, accessories, and air supplies are stored in cabinet F1; make sure to use a spring that is not fully compressed when relaxed (spring needs to both contract and expand). An air track is currently set on the tables under the clock when not in use. For more info, see Air Track Collisions.