DENJIRO: This is an episode of the four-part "Summer Vacation Science Project Special." We’re almost halfway through summer vacation now. Today's theme is this: the air vortex cannon. Let's shoot the cannon at a target.
The air that leaves the cannon is knocking down targets. But we can't see the air that is being shot out. So let's make these bullets of air visible. I'll first teach you how to make an air vortex cannon. You first need a cardboard box like this. Tape tightly the openings of the box with tape. Don't forget to tape the inside as well. We don't want the flaps inside to move. Next, you make a hole from which air will exit. Once you make the hole, the cannon is ready, but there's one more important point.
We're going to bend the corners like so. This will make it easier to push air out of the cannon. Hold the cannon with one arm, and use the other hand to push the folded side in to fire the air inside the box.
Let's now make the air vortex cannon bullets visible. We will put incense smoke inside the box. Let's fire the cannon.
GIRL: I see a ring of smoke!
DENJIRO: As you can see, we've made the bullet flying in the air visible. If you look closely, you can see that the smoke spins as it travels. The bullet of an air cannon flies as it pulls air from the inside to outside of the ring. This is called a vortex ring. It is this vortex that allows the ring to travel straight.
NARRATOR: When recording the flying vortex ring using a smartphone, make the room dark and shine light only at the travelling ring for best results. Try different amounts of smoke and levels of light intensity to observe the motion of the ring.
DENJIRO: I hope energy will bring you all happiness. Our magic word is "Happy Energy!"
29 сен 2024
