July 21st, 2024

Praxis: Build your own boredom-busting rockets

By Medicine Hat News on July 22, 2017.

It’s a bird, it’s a plane, no it is your very own rocket! Do not be scared, this is a pretty simple rocket that should take only about 20 minutes for two people to make and will literally provide hours of fun, trust me. I hope this will help get over that midsummer boredom. Let’s get started.

*Remember to ask an adult before doing this experiment.


– 2 L pop bottle

– water

– bicycle tire pump with a needle adaptor

– cork

– heavy weight construction paper or cardboard

– scissors

– duct tape

– water

– outdoor location


1. Empty the contents of the bottle and remove the label. Rinse out if necessary so it is not sticky.

2. Cut out a nose cone from the construction paper for the top of your rocket. Use your imagination, design a cone so it is pointed at the top and will fit over the bottom of the pop bottle. Secure the cone in place with the duct tape.

3. Using the construction paper, make three fins of equal size for the rocket. Tape these fins equally around the bottle just below the top you just made. Make sure that the construction paper that you are using is strong enough so that the rocket can stand up on its own on the sidewalk outside.

4. Push the needle adaptor all the way through the cork. You may have to ask an adult to trim the cork if it is too long to get the adapter all of the way through.

5. Fill the bottle about 1/4 full of water.

6. Place the cork in the opening of the bottle.

7. Have an adult help you out. Place the rocket on the ground in a safe outdoor location. This means away from buildings, animals, siblings, vehicles, power lines, windows etc. Choose your location wisely.

8. Have all people stand back and never put your face over the rocket.

9. Connect the needle adapter to the bicycle tire pump.

10. Use your muscles and put a few pumps of air into the bottle. Go slow and watch what happens!

What is going on?

Rockets operate on a principle of Newton’s Third Law of Motion, that “for every action there is an equal and opposite reaction.” This is demonstrated by your bottle rocket. The bottle rocket you made is filled partially with water and then sealed. You pump compressed air with the bicycle pump into the bottle. As you pump air into the bottle, the pressure is built up and is pushing on the cork. There is a certain point in which the bottle is not strong enough to hold the cork in any longer and it will let loose. This allows the water to be pushed out by the air, launching the rocket high (hopefully) into the sky.

Real rockets use a similar principle to fly high into the sky. Instead of squirting water out the bottom of the rocket, they burn liquid fuel which turns out a hot gas strong enough to send the rocket into space.

Try adjusting the amount of water in the bottle before you blast off — this may affect how high you can get your rocket to go. Good luck and be safe.

Patty Rooks is senior scientific consultant at PRAXIS, “Connecting Science To The Community.” Contact Praxis at praxis@praxismh.ca, http://www.praxismh.ca, Tweet or follow us @PraxisMedHat, or friend us on Facebook.

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