One of the hazards of being known as an MIT nerd is being tapped to teach “STEM” to kids. Here’s what I have learned about teaching 2nd and 3rd graders…
Their budget of sitting quietly and producing stuff on paper has been used up by the school system. Everything extracurricular should be hands-on.
The goal of the class was for them to understand how helicopters worked. So they needed to learn about Newton’s Laws, the Bernoulli Principle, how a wing works (combination of Bernoulli and Newton’s Third Law), how spinning a wing guarantees airspeed even when the fuselage isn’t moving (hovering!), and why you need a tail rotor if there is just one main rotor (Newton’s Third Law again).
It turned out that discussion around a table, drawings, and making posters on these topics wasn’t that interesting to the young scholars. However, getting some foam gliders and learning that they stall and spin without the supplied nose weight was quite compelling, as were a couple of trips to the airport to see real aircraft and finally actually fly in a real helicopter (we waited for a day without the 30-knot gusts that typically plague Boston in the spring).
If I were doing it again I would change the class to “How airports work” because the airport is concrete and there is lots of stuff to see and understand. The aerodynamics of planes and helicopters can be learned in this context. Models can be made. The control tower and fire department can be visited (if it is a big airport).
Now that they have *seen* and *experienced* helicopters and airports and had fun at it, you should be able to go back to your original plan have them work on Newton’s Laws on paper to connect the dotes to what they have *seen* and *experienced*. Have you tried this? My guess is they will now be interested in doing the work (promise them more trips as they get things right).
Good post. Interesting.
How does a wing work, anyway? I am familiar with the Bernoulli principle, where the longer path over the wing creates lower pressure on top of the wing. Lots of books claim this is the source of lift in an airplane wing. And maybe it is, in level flight.
However, it seems to me that airplanes also use plain old deflection of air (Newton’s third law), when taking off. Kinda like when I stick my hand out the window at an angle, and the air pushes it up. This doesn’t require an airfoil.
Is it both effects (as stated in your post)? I always wondered about this.
The best tutoring is going the way of Wright brothers, build a drone form scratch! I also noticed that going through different real exercises, as visiting antique machinery shops and trying to run exposed gears, and trying to reproduce real experiments, as hanging pendulum form a tall tree, etc.. have better educational effect, when paired with more work. Let kids fly a kite (an build it).
When I learned how to teach skiing they taught us that everyone learns differently. Some people see things to learn to learn them, some do things to learn (boys), some read to learn and some can just think about things and learn them. But we also learned that most people learn with a combination of these methods. So the fastest learning was to see a ski technique (teacher demo), be talked through the technique, read a paper (one page with pictures) about the technique and then be asked to do some actual skiing using the new technique. We found that most people learned to do stuff in a hour with this method.
But we also learned that people never learned how to do the ski technique if we just talked about it and showed them a paper view or some videos in a class room setting. Most people “never got it”. Even If we took them outside later they still never got it. We had to almost start over with the teaching.
So we concluded most people need to do something and see something and hear something and then think about something all at once to totally learn something completely.
So showing kids a big helicopter and then letting them play with a drone helicopter and then setting down and talking and reading and thinking about lift principles and Newtons laws should work fast. Especially if they were given some incentive like a real test ride if they passed a test. I bet they would have fun as well as understand flight.
Good Luck.
I also think this “doing” is why lots of home schooled kids learn so well. They do lots of stuff while learning about the math and history and geography and so forth behind the paper. Where the public schools try to teach most stuff with paper and little do or see. And giving them calculators and computers to do the math and research makes it worse. The kids never do the math or the library work so they never learn the basics. IMO.
My twins (kindergarten) recently visited a small airport with a hanger that rotates the planes inside (!) here in Germany. They let this kids crawl into one of the planes and touch controls. My only thought after seeing those pics was what a huge safety hazard that might be for the owner of the plane since who knows how many buttons were pressed by all those kids. He probably had to spend some time afterwards to make sure all the settings were back to normal. I don’t think I would get into a plane after a crowd of toddlers had passed through the cockpit.
Those kids may have violated the most important rule of flying heavy jets: If a switch has dust on it, don’t touch it!
(See http://armaerospace.com/ for how you can stack airplanes in a hangar.)
I still remember my fifth grade class trying to fly our creations, as well as the long “lane” of water in the hallway with a fan that we sent invented sailboats down. That was fun. And if there was math to make one better than the next guy, we learned it.
If Bernoulli and the path taken by air was the whole story, no plane could fly inverted.
For inverted flight many aerobatic wings are symmetrical and do not depend on Bernoulli. The rudder is also symmetrical.