Grouping: Individual
Take-home: CD balloon hovercraft
Key ideas: Air pressure, air cushion, friction reduction, flow rate and repeated testing.
Start with: Slide a CD normally, then run a completed hovercraft beside it and compare friction/motion.
Success check: Measure hover time or travel distance over three trials; improve one airflow variable.
Try changing: Balloon inflation; outlet-hole size; added mass; surface smoothness.
Preparation: Collect discs/caps; securely attach caps before class or supervise low-temp hot glue; set smooth test lane.
CNC preparation: Optional airflow-hole test stickers/templates.
3D-print preparation: Optional 3D-print safe reusable valves if desired.
Lesson flow: Day 1: Build → glide trials → change one variable
Video:
Build a Balloon Hovercraft
Safety and cleanup: Balloon/latex allergy alternative as needed; supervised hot glue; no deliberate balloon popping.
https://www.sciencebuddies.org/stem-activities/hovercraft
https://www.youtube.com/watch?v=tNDI7XxTDDE