2-L Rocket Eggmission
The Soda-Bottle Rocket Egg Launching Mission
(∆x ≥ 30 m)
1. Q focus - Rocket Science
1) What angle should the rocket be launched at for optimal flight?
2) How should the rocket be constructed?
3) How does the amount of water affect the rocket's flight?
This project can answer some if not all these questions because in the making of the rocket and the failures and successes, there are certain ways a rocket has to be constructed for it to actually fly and not explode at launch. There is a range of water the rocket should have depending on how much mass it has, so it can take off and fly properly. And angles also determine how high it goes and how far it goes. So launching the rocket should give a basis of what the rocket needs and should encapsulate all these questions.
2. Making of your Rocket
Here is the final product.
Materials Used:
- hole puncher
- clear scotch tape
- strapping tape
- string
- black trash bag
- cheap 44 cent folder found at Walmart
- (x2) 2L bottle
- scissors
- foam circle
- masking tape
- duct tape
- egg
- CD's
- clay
- camera (to take pictures of the process)
Photograph Evidence
Tutorial:
- Get all of the materials needed.
- Use scissors to cut out a 144in^2 square from the trashbag.
- Put one piece of tape at each end of the trashbag (should have 4 total). This should secure the trashbag from tearing when pole punched.
- Hole punch each end of the trashbag (4 holes total).
- Get string and measure and cut out 4 equal lengths of string, each 25 inches long.
- Tie the ends of the string to the trashbag.
- Remove all labels from the 2L bottle.
- Get one of the 2L bottle and cut the ends off of it, you should be left with only the body of the bottle.
- Take the other bottle rocket and secure it with strapping tape. Tape around it twice to ensure that when the body of the rocket is filled, it can withstand the pressure and not burst.
- Take 2 CD's and cut them in half. (you should have 4 CD's) and use these as fins.
- Attach fins to the bottle that has the strapping tape and secure it in place with duct tape.
- Attach the body of the bottle of the cut up rocket to the rocket that is secured with strapping tape. Tape the two together using strapping tape.
- Take out the foam circle and cut it in half.
- Hollow out the inside of the foam on both halves so that the egg can be fitted in snugly.
- Place the egg into a ziplock bag.
- Take that egg and place it inside the foam and close it with the other foam and tape the two foams together so that the egg is encased in "another egg shell."
- Place that egg shell inside the body of the bottle of the rocket.
- Tape the egg shell to the body of the bottle so that it doesn't fly out when launched.
- Take the cheap folder from Walmart and roll it up into a cone.
- Take clay that I "borrowed" from Ceramics class and place it at the top of the cone. Smear the clay around the top so that it stays at the top and doesn't fall back. Take layers and layers of more clay and apply so that it sticks heavily and durably. (This should ensure that the center of mass is heavily concentrated at the cone.)
- Take 4 strings of 12 in. length and attach the string from the cone to the body of the bottle of the rocket (the inside of the rocket not the outside). Secure the string with tape. Taping both ends of the string.
- Now attach the "trashbag parachute" to the rocket by taping the 4 ends of the trashbag strings to the ends of the rocket in a way so that the strings are spread out so it works like a parachute. (all on the inside of the rocket of course.)
- Take the parachute and fold it up into the cone.
- Place the cone onto the top of the body of the bottle of the rocket and loosely secure it with tape.
- Time to fly.
3. Physics of Rocket
According to this diagram from my professor, Thomas Zook, there are four rocket zones. And I'd also like this time to say that this diagram was found on canvas.hbushd.edu specifically at this url: https://canvas.hbuhsd.edu/courses/69/files/15724?module_item_id=665. "Copyright Disclaimer Under Section 107 of the Copyright Act 1976, allowance is made for "fair use" for purposes such as criticism, comment, news reporting, teaching, scholarship, and research. Fair use is a use permitted by copyright statute that might otherwise be infringing. Non-profit, educational or personal use tips the balance in favor of fair use." Happy Zook? In the initial stage of the rocket at the prelaunch. The rocket is being held back by the tension and pull force of the string, and pressure is being exerted on the rocket so it wants to go forward. A lot of potential energy is being built and stored up in this stage because work by the environment (some kid pumping) is done on the system (the rocket). In the 2nd stage of the rocket called "water everywhere", the rocket is released so now the potential energy of the rocket has been converted into its kinetic energy, so now the rocket is going forward. Once the rocket reaches the 3rd stage which is when it runs out of fuel. The rocket stops accelerating (by itself but still accelerates due to the pull of gravity) and now is going at a constant speed; we cannot say velocity because the wind is affecting the direction it is going in. Well actually, there wasn't any wind that day because it wasn't a windy day but there is some air resistance though that the rocket has to go against. And since the rocket is out of fuel, it gets to its highest point and then begins to be pulled down by gravity. When at its highest point, the vertical velocity is 0. The rocket then cruises down towards the ground due to the pull of gravity. This falling towards the earth that the rocket is doing makes it a body in "free-fall." At it's final stage, touch down, the rocket makes impact with the ground and it is a very inelastic collision because the rocket does not completely conserve energy, energy is transferred from the rocket to the ground but we cannot say it is perfectly inelastic because the rocket doesn't stick to the ground but hits the ground and keeps bouncing.
4. How does your rocket protect the egg from breaking
As said in the tutorial, the egg was secured with a foam egg shell. So that when the foam hits the ground it absorbs the force of the impact so that the egg receives minimal shock. Impulse is force x times. We installed a parachute so that when it deploys, the time is greatly increased upon impact so the force that the rocket receives upon crash-landing is very little.
5. Results
The rocket went 36m just barely clearing the minimum 30m requirement. Lucky us. The egg also survived. Not surprisingly. We launched it at a 45 degree angle, and we used 700mL of water. The two defaults. Everything went right, since we did clear 30m and our egg survived. No complaints However, for what we were doing, what went wrong was the parachute didn't deploy. The nose cone of the rocket did not fall off so that the parachute could expand and deploy, and also it wasn't a windy day. Supposedly, what was suppose to happen (in my head) was that since we placed alot of clay at the top the cone, it should have made the cone be heavy and so when the rocket was falling towards the earth, the cone should have came off the rocket so that the parachute can come out. But it didn't. And at the test launch, the rocket exploded and the fins died but the parachute did deploy and the rocket came back to the prelaunch site...Ironically, the egg somehow kept going forward and died, defeating the purpose of having a parachute in the first place.
6. What did you learn?
I learned the physics behind a rocket's flight and how to construct a rocket to adhere with those physics. I also learned that having a center of mass for the rocket was very important and having weight towards the top counteracted and balanced with the weight of the rocket from behind (the water in the rocket). And I also learned that the best form of protection for an egg is probably a foam shell. It seems as though this is the best protection. It beats cotton and bubble wrap and everything. You name it. But importantly, a cone to take the most damage while the egg is securely secured in the body of the rocket is what was most important in the egg's survival. Most people didn't have a cone, and so while they went further, they forgot the essential element of protecting the passenger. What good is a plane if it gets you somewhere, but none of the passengers survive? In conclusion, rockets are one of man's greatest discoveries and inventions. And physics is another. Combining these two should lead us into a better, brighter tomorrow. God that was cheesy.,
