Siren sound disks & air siren
Thank you very much @BruceYeany for the inspiration! Based on his designs I built my own which works really well to demo compression waves (sound waves) when a stream of air get chopped by the moving holes per unit time. The more holes (on the outside), produces the most chops per unit time and hence a higher frequency or pitch of sound. Only the number of holes affects the pitch per unit time.
The evolution of these siren disks culminated in the development of air sirens demonstrated by the little cute but extremely LOUD 3D printed version at the end of the video.
#sirendisks
#airsiren
#physicsdemos