Mathematically speaking, this particular flying object shouldn't be able to fly. What do you think about that?
Why can this thing fly? It doesn’t even LOOK like a plane! When I teach at the university, this is the plane that mathematically isn’t supposed to be able to fly! There are endless variations to this project—you can change the number of loops and the size of loops, you can tape two of these together, or you can make a whole pyramid of them. Just be sure to have fun!
It's actually a bit complicated to explain how this thing flies when "mathematically" it isn't supposed to, but here goes: there are FOUR forces at work with your flying machine. Gravity is always pulling it down, but air pressure keeps it up (called lift). The way real airplane wings generate lift is by having a curved surface on the top which decreases the air pressure, and since higher pressure pushes, the wing generates lift by moving through the air. (If this idea doesn't make sense, be sure to watch this video first!)
Ok, but what about a flat wing?
If you drop a regular sheet of paper, it flutters to the ground. If you wad it up first, you’ll find it falls much faster. The air under the falling paper needs to get out of the way as gravity pulls the paper, which is a lot easier when the paper is wadded into a ball.
For a flat wing (like on a paper airplane) to glide through the air, it needs to be balanced between gravity and the air resistance holding it up. In order for a glider to fly, the center of pressure needs to be behind the center of gravity (learn more about center of pressure and center of gravity in the third video below). By adding paper clips to your paper airplane, you move the center of gravity and center of pressure around to find the perfect balance.
When designing airplanes, engineers pay attention to details, such as the position of two important points: the center of gravity and the center of pressure (also called the center of lift). On an airplane, if the center of gravity and center of pressure points are reversed, the aircraft’s flight is unstable and it will somersault into chaos. The same is true for rockets and missiles!
Let’s find the center of gravity on your airplane. Grab your flying machine and sharpened pencil. You can find the ‘center of gravity’ by balancing your airplane on the tip of a pencil. Label this point “CG” for Center of Gravity.
Materials:
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- sheet of paper
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- hair dryer
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- pencil with a sharp tip
My bomber worked SO WELL! I used to be SO frustrated with bombers. You made it super easy!
I love it!!!!
Center of gravity describes the balance point of the aircraft. Center of pressure describes the cumulative effect of lifting forces on the aircraft.
The four forces involved in flight are lift, thrust, drag, and weight.
Is centre of gravity and centre of pressure forces.
What is the other 2 forces at work with the flying machine, because you’ve said that there are 4 forces.
Most folks can start with the appropriate grade level for their students, and after you’ve completed those, you can dig it more by subject (that way you won’t miss anything!). And remember, you don’t need to do all the experiments to get a great science education – there’s a lot of overlap so you don’t have to commit to each one. Just pick and choose the experiment lessons you’d like to do and progress from there. You’ll find assessments you can use at the end of each section within each grade level.
Personally, before I get started on a big endeavor like planning what to learn or teach for the year, I first write out what my educational goals are for the year. What do I want them to know, understand, and be able to do by the end of the year? (it’s kind of like planning out your weekly meals before you start shopping, so I can feel great walking out of that store with things I really need, instead of what’s most enticing when I walk by).
That said, with the program, if your goal is to interest and excite your kids about science, then it’s ok to hop around to the things that interest them most and you don’t really need as rigorous of a scientific notebook/journal as much as a science scrapbook photo album of their progress (if that suits you). If you’re preparing them to really think like a scientist and learn the process of how to do science itself, that’s going to have a different approach, as will preparing them for high school. What you do with the program is also going to depend on what kind of documentation your local state requires at the end of the year.
If you need to keep a science journal, you’ll find how to do that here: https://www.sciencelearningspace2.com/category/resources/keeping-a-scientific-journal/
I would first figure out your educational goals and then it will be easier to figure out how to meet that goal – use this approach for any curriculum, not just ours. Hope this helps!
I was inquiring about how to go about using the science with a 5th grader and an 8th grader? Do I start a notebook for them? Will there be worksheets for comprehension? Are there tests or quizzes?
That’s an interesting idea… you can try, and then let me know what happens!
Are you supposed to put a 3rd circle in the middle?
cool! we built this and it was great.
wow its amazing
Yes! Take a look at the responses/comments! 🙂
Hi. Can you explain how they are able to fly?
Try it! 🙂
Thanks for teaching me.
What if you place a third ring in the middle of the stick?
Really liked the video! 🙂
Really cool! 🙂
fun experiment for our 12 & 13 year old girls. though we are not able to explain why they fly. maybe has something to do with the airflow through the circles creating the appropriate draft needed? we did discover that attempting to fly it with the larger circle in the front is unsuccessful.
I think it flies because the bottom half of the circle wing is creating a dihedral shape and dihedral creates lift. Is that right?
So simple and fun! We did not have straws lying around, so we used a paper towel roll and cut it and rolled it to make it smaller. We doubled up on the weight of the index cards. It flew so far and my son was thrilled! Cannot wait to get to the store and try it with the straw!
That depends on what you want them to get out of the experiment. If it were me, I would point out the 4 forces (lift, weight, thrust and drag), and then show that the lift is coming from the ring surfaces. You can blow over a single sheet of paper and show how the sheet rises up when air goes over it quickly, just like the Ring Thing glides through the air. That might be enough for now. 🙂
Hi Aurora. How do I explain how this works to my 5 year old?
Who knew a straw and two strips of construction paper could be so fun?! 8 thumbs up! 🙂
Here’s a hint: there are four aerodynamic forces: lift, weight, thrust and drag. Can you identify these in your flying machine?
Well, I was talking with my dad about it, and every time, I developed a theory, he showed me why it was wrong. He says he doesn’t understand, either, but he thinks it has something to do with Bernoulli’s Principle. But I think if it were Bernoulli’s Principle, it would be mathematically able to fly!
Great questions! What do YOU think?
How does this work? How does it glide? Why is it mathematically not supposed to be able to? Why doesn’t it work when you throw the big circle first?
Yes they are supposed to. Let me check with my tech team and get right back to you. You’re sure you’re logged in?
The video won’t play on my Samsung tablet. Using Chrome. I thought the videos would play on all devices?
What device are you viewing this on, and what type of web browser?
This video doesn’t play for me!
What can i do to fix the problem?