It’s simple physics—a moving object will continue forever at a constant velocity unless it’s acted on by an external force. To the physicist, Newton’s First Law is second nature. Yet it’s still fascinating to watch an air track glider moving endlessly back and forth on an air track.
It’s even more fascinating for students, who are often seeing this simple display of motion for the first time.
Add a timing system to investigate uniform motion, average and instantaneous velocities, uniform acceleration, elastic and inelastic collisions, impulse and change in momentum, conservation of momentum, conservation of energy, and more. The data is precise and unambiguous and frictional forces are negligible.