| Every flying thing, whether it's an airplane, | | | | underside of the cups and release. The cups |
| spacecraft, soccer ball, or flying kid, | | | | should rotate quickly and take air, then |
| experiences four aerodynamic primary forces: | | | | gracefully descend down for a light landing. |
| lift, weight, thrust and drag. | | | | Try making one with four cups. |
| | | | |
| An airplane uses a propeller or jet engine to | | | | Hot Air Balloons: Shake out a garbage bag to |
| generate thrust. The wings to create lift. | | | | its maximum capacity. Tape (use duct or |
| The smooth, pencil-thin shape minimizes drag. | | | | masking tape) the open end almost-closed... |
| And the molecules that make up the airplane | | | | you still want a small hole the size of the |
| attributes to the weight. | | | | hair dryer nozzle. |
| | | | |
| Let's find out what are all the parts of an | | | | Use the hair dryer to inflate the bag and |
| airplane for. You'll need to get a cheap | | | | heat the air inside (make sure you don't melt |
| balsa wood airplane for this next part - | | | | the bag). |
| check out your local drug store or toy store. | | | | |
| I've even found them in grocery stores for | | | | When the air is at its warmest, release your |
| about $2. | | | | hold on the bag while you switch off the hair |
| | | | dryer. It should float up to the ceiling and |
| Take the balsa wood airplane and try to fly | | | | stay there for a while. This experiment works |
| just the body (no wings or fins). It flips | | | | best on cold mornings. The greater the |
| all over the place. Try flying just the large | | | | temperature difference between the bag's air |
| wing (no body). Somersaults! | | | | and the surrounding air, the longer it will |
| | | | float. |
| Now slide the large wing into the body and | | | | |
| fly (fewer somersaults, but still sickening | | | | Parachutes: Attach a piece of floss or thin |
| to fly in!). | | | | string to the four corners of a tissue. |
| | | | Attach a stick, a small wad of stones wrapped |
| Now add a horizontal stabilizer (elevator) | | | | in another tissue, a pinecone, etc. to the |
| tail, and when you throw it, add a slight | | | | centers of the string. Practice dropping |
| curve so the plane "fishtails" in the air | | | | these from the balcony and see which falls |
| (like a car)... but did you notice that there | | | | slowest with which load. |
| are no more somersaults? | | | | |
| | | | Ring Thing: Cut an index card into thirds |
| Add the vertical tail (rudder) and see how it | | | | lengthwise. Loop one strip into a circle and |
| now steers straight no matter how to | | | | tape ends together. Place two remaining |
| curve-throw it. | | | | strips together end-to-end and tape, then |
| | | | loop into large circle and tape in place. |
| Sneaky Tip: if you remove the metal clip on | | | | Place a piece of tape across one end of a |
| the nose beforehand, you can add it last to | | | | straw and gently secure one ring to the tape. |
| really see what it's for... notice where most | | | | Repeat on the other end with remaining ring. |
| of the weight is without the clip? | | | | Make sure the two rings are concentric (you |
| | | | can see through both like a telescope). Throw |
| Let's make more things that demonstrate these | | | | it small-end-first! |
| flying ideas! | | | | |
| | | | Free Form Machines: Make an obstacle course |
| Helicopters: Cut out a paper rectangle 5 by 2 | | | | with some or all the following different |
| inches. Cut lengthwise down the strip, | | | | challenges: |
| stopping about an inch before the end. Tape | | | | |
| this uncut inch to the end tip of a popsicle | | | | -Hit a target balloon (arm the machines with |
| stick. Fold the "bunny-ear" flaps down in | | | | opened paper clips) |
| opposite directions. Throw off a balcony and | | | | |
| watch it whirl and gyrate! (Optional: You can | | | | -Go over and under a suspended length of |
| notch the end of the popsicle stick to make a | | | | string |
| sling-shot helicopter. Make a quick slingshot | | | | |
| launcher by looping a rubber band to another | | | | -Make it through a hula hoop suspended |
| popsicle stick end.) | | | | vertically or horizontally |
| | | | |
| Butterfly Cups: Tape two Dixie paper cups | | | | -Carry a jelly bean passenger safely across |
| together, bottom-to-bottom. Chain together | | | | shark-infested waters (two tables spread |
| six rubber bands. Loop one end of the rubber | | | | apart) |
| band chain over your thumb and hold your arm | | | | |
| out horizontally straight, palm up. Drape the | | | | -Dangle large paper airplanes (made from |
| remainder of the chain along your arm. Place | | | | 11x17" paper, or two 8.5x11" papers taped |
| the taped butterfly cups at the free end | | | | together to make an 11x17") from the ceiling |
| (near your shoulder) and slowly wind the | | | | for a 'dogfight' to earn points if you tag |
| rubber bands around the middle section of the | | | | one |
| cups. When you wind near the end, stop, | | | | |
| stretch the chain back toward your elbow, | | | | -Shoot through the basketball hoop, and dive |
| make sure the rubber band comes from the | | | | into a basket. |