Fizz Rocket
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World Almanac for Kids
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A completed fizz rocket
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Did you ever see a rocket taking off? It climbs into the sky on a pillar of fire. But how exactly does it work? You can get an idea by building your own rocket and launching it. (For safety reasons, be sure to have an adult with you when you're doing this.)
- A 35-mm film canister with a cap that fits inside the rim -- a photography store may have extra ones they'll give you if you explain it's for a science project.
- A fizzing antacid tablet, the kind sold to cure upset stomachs.
- Paper -- a few sheets of normal printer paper are fine.
- Scissors and tape.
- A cup of water.
- Goggles or sunglasses or something similar to wear as eye protection.
1. Make the body of the rocket -- a cylinder -- by cutting a strip of paper, then taping it to the film canister. Make sure the cap end is at the bottom!
2. Make a nose cone for the rocket by cutting a circle out of the paper, then cutting a wedge out of the circle.
3. When you tape together the edges of the wedge, you'll get a cone.
4. Have fun with your rocket design -- you can add fins if you want. Try short or tall rockets, and make the nose cone more or less pointed.
5. Take your rocket outside and put on your eye protection.
6. With the rocket pointing down, fill the canister about one-third full of water.
7. Drop half the antacid tablet in the canister. Then quickly put the cap back on, turn the rocket right side up, and put it on the ground for blasting off.
8. Stand back and see how high it goes!
Rockets -- yours and the ones NASA sends into space -- work because of Newton's Third Law of Motion: for every action there is an equal and opposite reaction. In the fizz rocket, the antacid tablet dissolves in the water and releases bubbles of gas. In a balloon, which is elastic, the gas would blow up the balloon. But the film canister in the rocket isn't elastic; the bubbles build up pressure until finally they pop out the cap. The cap and water rush out in a downward direction, and the rocket blasts off in the opposite direction -- toward the sky. Real rockets, of course, use a different fuel, but the same basic principle.
Ciencia: Cohete efervescente (Spanish Version)