If you are called upon to explain about airplanes to kids
who really don't know any physics, e.g. Cub Scouts, here
are some suggestions:
1) Find somebody who has a small aircraft.
2) Take the kids down to the airport. Take PLENTY of adults
so that you can control the kids; you don't want them
running loose on the ramp where they might encounter a
spinning propeller. Trap N-2 of the kids in the FBO
office or pilot lounge.
3) Take the kids two at a time out to the airplane. Let
them sit in the pilot seats and wiggle the control yoke.
Get them to look over their shoulder so that they can see
the control surfaces move as they move the yoke.
4) When everybody is back inside, do the fluttering card
demo. http://www.av8n.com/how/htm/airfoils.html#sec-spinners
I tell them this is all the theory they are going to get
right now, and I do not expect them to see the connection
between the card demo and the actual wing behavior ... but
nevertheless there *is* a connection, namely circulation.
Someday somebody will try to explain how wings work, and
if he doesn't explain it in terms of circulation he doesn't
know what he's talking about. We warned that there are
lots of wrong explanations out there. Any so-called explanation
that doesn't center on circulation is guaranteed to be wrong.
5) Everybody makes a paper airplane using the pattern at http://www.av8n.com/fly/pdf/flyer.pdf
These airplanes fly well, and they have a blunt nose so it
is relatively hard to put somebody's eye out.
Practice trimming the airplane so it flies straight.
Practice trimming the airplane so it flies slow.
Practice trimming the airplane so it flies faststraight..
There's really no point in "explaining" the facts until the
kids know what the facts are. A few hours playing with paper
airplanes will give the kids a much better grasp of the basic
facts. Of course as always theory reinforces experience and
vice versa, in the usual itsy-bitsy-spider way. http://www.av8n.com/how/htm/intro.html#fig-lattice
For example, they weren't born knowing that airplanes even
/have/ trim, so they're not going to experiment with trim
unless you tell them to.
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In high school, the "paper airplanes" unit is suitable for the
last day of class before vacation. Hint: Warn the other teachers
that there is a chance that some of the "experimental apparatus"
might escape into other classrooms. Tell the kids "If you
think it would be highly original to take a couple of airplanes
to history class and fly them across the room, well no, you're
not the first teenager to think of that. Nobody is going to be
impressed with your cleverness. If you want to do fun things
like airplanes in physics class, you have to demonstrate some
sense of responsibility. Fold the thing flat inside your physics
book and leave it there until you get home. Now that you have
the pattern you can make a ream of them when you get home, if
you want. They actually make good presents, if you have younger
siblings. I've yet to see a kid who didn't want one."