Science Smarts: Build your own rocket
By PATTY ROOKS on July 23, 2021.
I do not know about your household, but there is a bit of midsummer boredom occurring around here … With the never ending heat, it is hard to find a fun outdoor activity to keep cool these days. This week is sure to not disappoint. I guarantee participants will get the odd cool spray when trying to figure this one out! Let’s get started. Remember to ask an adult before doing this experiment. Materials • Empty 2 L plastic pop bottle • Cold tap water • Bicycle tire pump with a needle adaptor • Cork • Heavy weight construction paper or cardboard • Scissors • Duct tape • Outdoor location Procedure • Remove the label, and rinse out the empty pop bottle. You want it to be nice and clean, not sticky! This will just create more of a mess… • It is time to design your rocket. Using the construction paper, roll it up to create a nose cone 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 (bumpy end of the pop bottle). I know this seems backwards, but trust me! • Now is not the time to spare the tape, secure the cone in place with a LOT of the duct tape. Use a good quality, waterproof kind if at all possible. I really like the black variety. • The rocket needs to fly high in the sky, so you need to make some fins on the side. 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. • Have an adult help you push the needle adaptor all the way through the cork. It needs to be all of the way in there and secure. • Fill the bottle about ¼ full of water. • Push the cork into the opening of the bottle. Make sure it is in there nice and tight! • 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. • Have all people stand back and NEVER put your face over the rocket. • Connect the needle adapter to the bicycle tire pump. • 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, “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, Senior Scientific Consultant 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. Find us at #12 826 11 Street S. E., Medicine Hat, Alberta, T1A 1T7 Phone: 403-527-5365, email: praxis@praxismh.ca. 30-29
