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Glider Boy

Media Type:
Video

Running Time: 2m 48s
Size: 8.4 MB

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Source: ZOOM

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In this video segment from ZOOM, a paper glider enthusiast shows off some of his creations. The gliders he has made -- both small and large -- demonstrate his understanding for how things fly as well as which household materials are best for constructing small, non-powered aircraft.

Background Essay

The same three basic forces that act on full-sized passenger airplanes during flight also act on hand-launched gliders: gravity, lift, and drag. The force of gravity is determined by the weight of an object. How the weight is distributed along a glider is even more significant than its total weight. The point at which a glider will balance on your finger is called its center of gravity.

When air pressure acts on the wings and pushes the glider upward during flight, we call this force lift. In order to fly, the wings of a glider must produce enough lift to overcome the force of gravity acting on the aircraft. The amount of lift is influenced by the surface area of the wings, their shape, and how they are angled. Wings with greater surface area are subjected to a larger volume of air pushing up on them. An airplane's wings are generally curved on the top and flat on the bottom. Air flowing over the wings travels a longer distance than air passing under the wings, and, as a result, it flows faster. When air flows faster, pressure drops. Thus, the air pressure under the wings is greater than over them. With more pressure pushing up on the wings than pushing down, the plane stays aloft. Fixing the angle of a flat wing -- like that used for a paper glider -- so that it rises slightly toward the front produces a similar effect.

Drag, also referred to as air resistance, is the force that causes a glider to slow down in flight. A powered aircraft has engine thrust, which is the force that propels to overcome drag, but a glider does not, and so it must be designed in a way that minimizes drag. You should use wing material that is smooth and thin so that the surface offers little resistance to the air. You can also increase the lift-to-drag ratio -- which improves aerodynamic efficiency and increases range -- by designing a glider with longer wings. Because paper is not very strong, you might choose a stiffer material that can span a long distance without drooping. Alternately, you can build a frame for your wings from wooden dowels and stretch lightweight material such plastic wrap around them.

Discussion Questions

• There are many different kinds of gliders in the video segment. What do they all have in common that helps them glide?
• What is the energy source that starts a glider moving?
• What is the difference between gliding and flying?
• What materials does Jesse use to make his gliders? What do the materials have in common?
• In the design process, testing the model or prototype is useful. What does Jesse learn from his testing?
• What animals can you think of that move by gliding?

• Transcript

(footsteps approaching) (knock on door) (hinge squeaks) (chuckles)

JESSE VANDERDOSE: I’m sorry. You see that? That flew. My name's Jesse Vanderdose and... I'm 12 years old. I build gliders and try to make them fly. I use toothpicks, plastic and duct tape. I've used tin foil and newspaper and index cards and electrical tape, milk bottles, soda bottles.

These are gliders. It's basically an airplane that you throw, and in the case of this size of glider, it is more of a parachute effect. When you throw it, a lot of air catches up underneath it and it picks it up.

Do you want to see some of my gliders? This is a dart plane. The problem with really big dart planes is they're really floppy, so what I did was I added popsicle sticks here like struts on a little prop plane. Gliders can be pretty simple and still work.

This is a funny one. I don't know why I made it. I made it out of index cards, electrical tape, armature wire and a matchbox. This flies really well if you can get the tail positioned right. It doesn't have to be perfect. I was working with the idea of a delta wing because delta wings seem to work best. And I made it out of duct tape and plastic that you use to insulate windows and a soda bottle.

This is my friend Mike. And he came over so that we can work on some modifications for the biplane. You start learning a lot about what makes a plane fly. A lot of the time it doesn't work and it just crashes and burns and stuff. Then you just go back and you work on it, and a lot of the time it works. I don't know, it seems like If you put wings on it and then you throw it, usually you can make them fly. Oh, wait a minute. I got one more plane I got to show you.

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