|
|
||||||||||||
| Brought to you by KBears | ||||||||||||
Before the helicopter, before the airplane, there was the hot air balloon. You can build your own hot air balloon that runs on . . . what else? Hot air! To find out how this works, read the explanation and follow the links below for more information. Collect the materials below and follow the instructions to build your own hot air balloon. |
||||||||||||
|
Safety Information Experiments are dangerous, but scientists are always safe! →Always
have an adult help you collect the materials and conduct the experiment.
|
||||||||||||
|
||||||||||||
| → | Silk Paper (Get different colors) | |||||||||||
| → | Paper Glue | |||||||||||
| → | Scissors | |||||||||||
| → | Some cotton balls | |||||||||||
| → | Rubbing alcohol | |||||||||||
| → | hair dryer | |||||||||||
| → | matches/ lighter | |||||||||||
|
||||||||||||
| 1) |
Create 8 strips of 1.5 ft x 6 ft. silk paper. Stack them and fold the whole stack lengthwise.
|
|||||||||||
| 2) |
Cut the folded stack of silk paper
into the half-balloon shape as shown.
|
|
||||||||||
| 3) |
Unfold the strips, but leave them
stacked. Slide the papers one by one
so that there is about 1/2" flap between them.
Glue this flap and
fold it over to
connect the strips. Do this for all the strips, and
finally glue the top strip to the
bottom strip.
|
|||||||||||
|
4)
5) |
Open up the balloon and
blow-dry the glue to get it dry faster.
If there is a hole at the top of your balloon,
cut out silk paper and glue
it to the edges of the hole to make a patch. Shape the wire into a circle the size of your balloon's bottom opening. Make a wire cross through the circle as shown.
|
|||||||||||
| 6) | Make an egg-sized ball of cotton balls and keep them together using wire. Leave a little extra wire so you can attach the cotton balls to the center of the cross. | |||||||||||
| 7) |
Fill the balloon with hot air using
the hair dryer. |
 |
||||||||||
| 8) |
Dampen the cotton balls with the
rubbing alcohol.
Then, light them on fire. Once the balloon starts to rise, have all the people holding it let go at
the same time .
. . |
 |
||||||||||
|
Up . . . Up . . . and Awaaaaaaaaaay! Bon Voyage! |
||||||||||||
|
||||||||||||
| A hot air balloon works because it traps hot air inside, and hot air rises. Why does hot air rise upward? | ||||||||||||
| Hot air is less
dense than cooler air. Why?
First of all, all air is made of very quickly moving particles. When the air is hot, the particles move even faster. When the particles move faster, they push harder against cooler air. In our experiment, the air fills up the balloon. The air wants to keep going upward, but the balloon is in the way. Since the balloon is lightweight, its easy for the air to take the balloon along for a ride! |
||||||||||||
| Why doesn't the balloon keep flying into space? Because in the atmosphere of the Earth, as you get farther away from the Earth, it gets very, very cold. So as the balloon goes higher and higher, the air that's pushing it starts to cool down. When that happens, the air stops rising, and the balloon falls back down. | ||||||||||||
|
||||||||||||
| Balloon Fabric Experiment | ||||||||||||
| A student experiment determines whether polyester or nylon makes the best balloon fabric. | ||||||||||||
| Elephant and Feather | ||||||||||||
| Explains how air resistance slows falling objects | ||||||||||||
| Gravity | ||||||||||||
| Students explain what gravity is and how it works. | ||||||||||||
| Weather Fronts | ||||||||||||
| Explains why warm air rises and how this is connected to weather | ||||||||||||
|
© 2005
KnowledgeBears.com, Inc. |
||||||||||||
