Biological Flight

Russell C. Osantowski Bateman Elementary
4220 N. Richmond
Chicago IL 60618
(312) 534-5055


This lesson is for K-6th grades. Students will learn about the many
different ways that seeds fly in birds, in air, and why. They will collect
seeds, learn Bernoulli's principle including lift, ailerons, elevators, drag
and how to make a paper helicopter that simulates some seed flights. It
integrates botany, biology, zoology (how birds are built to fly), chemistry,
physics, and art with student drawings, tracings and a picture of Brancusi's
sculpture entitled "Bird in Flight."

Materials Needed:

Paper, pencil, scissors or paper cutter, scotch or plastic tape, (all of
the following are optional items you may wish to use and/or give to your
students) including carbon paper, stapler and staples, a photocopy of the
encyclopedia article regarding Bernoulli's principle, and a photocopy of the
Brancusi's sculpture cited above from any good encyclopedia.


1. Take the children outside to collect seeds and sometimes things that
look like leaves. Or have them bring to class different types of seeds they
find. Throw the seeds up into the air or drop them from as high as you can
reach, to illustrate how they fly. Explain that on a windy day many will
fly farther. Note: if you stand on a chair, your students will quickly
imitate you,
2. Cut a strip of paper, 2" by 8" and hold it to the tip of your chin with
your index finger. With your lips slightly pursed, blow air above the
paper in a thin fast stream. The paper should rise, because, according to
Bernoulli's principle, air or liquid moving faster than the things around
it creates low pressure in the flowing area. Therefore, the air underneath
it has a higher pressure and pushes up creating "lift". However, if you
put the edge of the paper beneath your nose, and blow a thin stream of air
beneath the paper it will also rise, but, this is due to the force and
speed of the air flow. It is not caused by Bernoulli"s principle.
3. Explain that the outer coatings of some seeds must be dissolved by the
digestive juices of certain birds before they can germinate. Therefore
their flight only ends when they are excreted, either by the bird in flight
or resting on a branch or after a baby bird in the nest excretes the seed.
Can you think of other animals that might carry seeds this way?
4. Dandelion seeds fly through the air by wind but burr type seeds fly by
sticking to the coat of animals or onto clothing of anyone, like velcro.
5. Maple tree seeds and other seeds fly like a helicopter and although they
are normally encased in a single wing, it twirls like a helicopter rotor
which is the large main blade that keeps it in the air. To make a paper
helicopter, take an average sheet of paper (8 1/2" by 11"), and fold it
lengthwise in half. If your class does not have scissors easily available
to them, just have them fold and re-fold the paper back and forth several
times. Explain that this folding weakens the fibers in the paper so that
it will tear much more easily and accurately.

Tear it in half. If the paper is lined, fold it in half again and tear it
from the top down 13 lines, including the one inch large space at the top
of the line. If the paper is unlined (plain), fold it lengthwise from the
top only one-half way down to the middle of the paper. Re-fold it several
times and along this vertical line tear it down only to the middle of
the paper. See the diagram below. Bend the wings about 30 degrees in
opposite directions.
________________ _________________ ________________
| one half of | | . | | |
| your | | . | | |
| original | | . | | |
| sheet | | . | | |
| of | | . | | |
| paper | | . | | |
| | | fold | | |
| | | and | |..... .....|
| | | tear to | | last |
| | | make the rotor | | fold |
| | | wings | | and tear |
|________________| |_________________| |________________|
| | |
| | |
| | |
| | |
| | |
|.......|........| Your finished product
| |
|_____ _____|
. .
. . Dotted lines are where folds must be.

Then skip about 1 and 1/2" and make sure you do nothing to this sort of middle
section of this paper. Gently fold the bottom of the paper up along this
imaginary horizontal line that is 1 and 1/2" below the bottom end of your
vertical tear.

This is the hard part. You must be very careful not to tear it too far in on
either side. We will now explain. On this horizontal line, tear in from each
edge only 1/3 of the way toward the center and stop. Now, fold in these two
sides so that each one exactly covers the middle side. You now have something
that sort of looks like a "Y". Hold it up as high as you can reach, and in one
motion, pull it down and let go at the same time, to make it fly.

Performance Assessment:
Oral questioning and discussion for the examples. Observation and/or grades
for the completion of the hands-on paper helicopter project.

This is a successful introductory lesson to a unit on seeds and parts of a
plant. Children will be bringing in examples of flying seeds long after this
lesson is over.
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