The elastic potential energy is related to the elastic deformation of the object, while the kinetic energy is related to the mass and speed of the object. A tightly rolled rubber band has strong elastic potential energy. When the car moves forward, the elastic potential energy of the rubber band decreases while the kinetic energy of the car increases. Therefore, the elastic potential energy is converted into kinetic energy. When the rubber band releases its energy, the car will continue to move due to inertia and eventually the car will stop. Kit is wood and can be painted! *See ADDITIONAL RESOURCES above to access our Teachers Resource guide pertaining to this kit.