KITES!!!

Bernoulli was a "BIRD_BRAIN"!

He discovered that fast moving air exerts less pressure than slow moving air. This principle makes airplanes and gliders fly. The wing is shaped so that the air going over the top of the wing moves faster than the air on the bottom of the wing. The air travels farther and faster over a curved surface than a straight surface. Because the air on the curved upper surface moves faster it flows at lower pressure than the slow moving air on the bottom flat surface. The higher pressure from below the wing then pushes it upwards. This makes the wing rise and keeps the plane in the air.

Create a stream of air at low pressure over a strip of paper. Equipment: A strip of paper! Method: You put a strip of paper under your lip. Blow over the top of the paper. Result: When you blow over the top, low pressure flows across the top. The high pressure pushes the paper up.

One of the more famous kite ariel photographs was of the San Francisco Earthquake in 1906, a camera of 49 pounds was lifted by 9 kites to a height of 2000 feet. The photo that was taken is shown below. This photo is courtesy of the Mars Kite Expedition which has just got to be the ultimate kite flying experience!

Four Forces of Flight

Gravity Heavier the kite, more difficult to get off the ground. Really!

Lift The force that stops a kite from falling. It’s produced by air moving over the top of the kite at a faster speed than the air that is moving over the bottom of the kite.

Thrust The force that makes something move forward through the air The kite is being held in one place by its string while the wind flows around the kite.

Drag The friction that keeps the kite from flying straight over your head. This is caused by roughness of the fabric and the spars. Additional drag is created by the tail of a kite.

What is a Tetrahedral Kite? Tetrahedrons are a regular 4 sided polygon. Basically a pyramid shaped framework which is the strongest structure known. A tetrahedral kite is formed when you cover two sides of the four sided figure and to join a number of these together into a large tetrahedral kite. http://www.cedu.niu.edu/scied/courses/tlci525/tetra.html

http://www.tonyshome.f9.co.uk/kites/gallery/gallery2001.htm

1st Item Building the Spars (the Skeleton) For each spar: You need 6 straws, 1 meter of string, two 35 cm of string.

Place three straws on the meter of string Place three straws on the meter of string. Then tie together to form a lovely equilateral triangle.

Next, Tie the two 35 cm pieces of string to the lower ends of the equilateral triangle. Place the straws on them.

Then, Tie the two 35 cm pieces of string together. Make sure that this string is long enough to put another straw on!

Finally, Place the sixth straw at the bottom and pull it up to tie to the original triangle.

Now Do Three More of These Spars

Sky is the Limit Mr. Bell's ultimate achievement with tetrahedral kites was a kite built of 3,393 cells, and was named the ``Cygnet'' (see photo right). The kite was towed behind a steam ship and actually carried a passenger, a Lt. Thomas E. Selfridge. After the initial flight however the kite was destroyed immediately after landing, before the steamer crew could cut the tow rope. http://www.cedu.niu.edu/scied/courses/tlci525/tetra.html

Photo # 1 -- "Cygnet #2, "a tetrahedral kite designed by D Photo # 1 -- "Cygnet #2, "a tetrahedral kite designed by D. Alexander Graham Bell, built at Baddeck, Nova Scotia, contains 3,960 tetrahedral cells covered with red silk and driven by same motor as the "Silver Dart." John A. D. "Doug" McCurdy pilot, February 22, 1909. Photo courtesy June Sturgis, daughter-in-law of early pilot Parker Brooks Sturgis http://www.airmailpioneers.org/antiques/Bell.htm