««« Submitted by Otto Wevers,
This little air cannon is so much fun and creates so much wonder, it is sort of incredible that the only versions seem to be the large scale monster air movers that need smoke to make them useful.
Big Idea
Conversion of energy requires a machine of some kind to change the input to an output. Moving particles in a gas cannot generally be seen, but their effect can be seen or felt.
Safety Note
Sharp cutting tools require training and safety glasses. Securely hold the plastic container in order to create/drill holes in the bottom of it. If you want to see the smoke rings, work in a reasonably well ventilated area and use a non-toxic smoke machine that can be easily controlled
Materials and Tools
- 2 L or larger clean plastic container with a flat bottom, handle, and a screw-on cap from a recycling bin (homework)
- hole saw or other cutting device that can create holes of various sizes in plastic containers
- sandpaper or other smoothening tool for removing burrs from the cut edge.
- a very thin plastic tablecloth or similar barrier to be hung up as a flutter target.
Procedure
- Cut various size holes into the bases of similar containers, leaving the lid on the container.
- Hang the tablecloth from a suitable place so it can deform easily to show the air puff from the cannon.
- Gently bash the side of air cannon with your hand while directing the hole at the tablecloth about 2 m away from the
tablecloth. - Observe the tablecloth’s deformation to see the effect of the gentle bash.
Questions
- Why might people be so surprised when they feel the puff of air?
- How does this demonstration explain how forces can act by contact or at a distance?
- What are the energy transfers and forces to make this air cannon work?
- How do the hole size or shape affect the usability/effectiveness of the cannon (or do they)?
- Can puffs of air have an effect on each other? How would you find out and know?
- What scientific and technological laws and principles can be demonstrated through this toy?
Extensions
- When you get good at aiming the air cannon, use it to play air tag with unsuspecting people.
- Why might people be so surprised when they feel the puff of air?
Credit where credit is due:
We’ve seen this in various large-scaled incarnations at STAO/APSO’s annual conference, including Steve Spengler’s presentations.
Curriculum Connection
This information is recommended for use with the Ontario Curriculum, Grade 1 Understanding Matter and Energy (Energy in Our Lives); Grade 6 Understanding Structures and Mechanisms (Air and Flight); Grade 8 Understanding Matter and Energy (Fluids).
««« Submitted by Otto Wevers, Courtesy of the STAO/APSO Elementary Curriculum Committee.