How to make an air cannon

Take a look out your window. You might see a leaf fall from a tree, or a bird fly through the air. What makes these things move? Things move when they are impacted by forces. Some forces require contact, such as a foot kicking a ball. Other forces are invisible and non-contact, such as gravity pulling a leaf towards the ground.

We might not be able to see it, but air is not nothing! We breathe in air, and it provides us with oxygen to sustain life. Air is a gas, a state of matter that expands to fill any container it is in. Like water, air flows and moves around us. These movements can be beautiful, complex and surprising. Our atmosphere is like an ocean of air. The winds are the currents and the birds and butterflies swim through the vast swells.

With an air cannon, the ejected jet of air pushes light objects around, touching them and pushing them around with a contact force.

Our Scienceworks challenge to you:

Get creative and change your design to make ultimate air cannon! What happens if you change the volume or shape of your air cannon, the size of the opening or the elastic material? Can you make your air cannon move confetti on the other side of the room?

Gather your materials: paper cup, thick pencil, tape, balloon, scissors, something light (feathers, pom poms, confetti, glitter or small bits of paper).
 

Use the pencil tip to push a hole in the bottom of the cup.
 

Stretch the balloon by inflating it briefly.
 

Tie the end of the balloon to make something to pull on and cut off the top on the other end.
 

Stretch the balloon over the mouth of the cup, making sure that the balloon handle is in the middle.
 

Tape it to the cup to secure.
 

Point the hole of the cannon towards something light. Hold on to the cannon while you pull back and let go of the balloon handle. Watch the invisible air push things around!
 

Try different things and different ways to make.