Bottle Rocket

The Rocket

My 3 Questions: QFT

Would Styrofoam or a sponge work in order to keep the egg safe?

Would angled fins work to make it more aerodynamic?

Which of the combinations (Long-narrow, short-narrow, Long wide, or short wide) would work the best?

         As I wrote this I didn't know what i was thinking. I figured that I wanted the farthest distance. On our first test run, we tried using sponges and made a sponge casing for the egg. Unfortunately, this did not work and this answered my first question. I saw the second answer to the next question on a source online. It stated that straight fins were the way to go. Also, it stated that the angles fins would make it turn and we did not want that to happen. Lastly the same source answered our question. Shorter and wider fins work just fine for the rocket to launch smoothly. 

Our rocket consisted of three fins, two bottles, styrofoam  cotton, and a metal nut. The fins were made out of plastic cardboard, a material vastly superior to regular cardboard, a Brisk soda bottle and and Coco-cola bottle

Steps for Building

1. Get two bottles

     

2. Cut one of the bottles in half, and keep the side with the nozzle

3. get a styrofoam ball and cut it in half

4. Scrape out an egg like hold in the middle of the styrofoam with a knife

5. Now put cotton balls in the top area of the bottle that was cut. 

6. Insert the styrofoam structure into the rocket, with egg inside the styrofoam.

7. Get the cap of the bottle and put a nut in it for weight

8.  Now for the fins. Get plastic cardboard and cut out 3 fins for the rocket

9. Attach the fins with duct tape and make sure they are evenly spaced

10. Done! Perfect Rocket.

   At first, we tried using only sponge for the cushion for the egg, and although it went 99 meters, the egg was completely broken. 

        Next tried out rocket with just styrofoam. This launched pretty far, around 60 meters, but it was very wobbly and unstable because the lack of weight. 

        Our last revision was with a metal nut in the cap of the rocket, styrofoam and cotton. On the day of final launch, it reached 87 meters, won the farthest with surviving egg, and made me very happy. 

Physics of the Rocket

sorry it is sideways. 

         First of all, let us take a dive into the world of forces applied onto the rocket. In section 1 As the rocket is placed into the launching pad, there is a normal Force being applied and gravity. Also when the pressure is being pumped into the bottle to make it launch, there is a force that is being applied by the gas inside which makes the rocket want to accelerate forward like in section 2. 
         
         Pressure and volume are inversely proportional and when volume stays the same, but the pressure increases, it creates a harder pressure for the rocket. When the washer releases and the rocket starts to fly, there is a force of air resistance, gravity, and the forces from the gas inside that pushes the water to make the rocket move forward. As all the water gets out, the rocket has no more "fuel" and cannot apply a force on something to make it move faster. Gravity is the reason that the rocket does not stop flying because it has a downward acceleration. Aside from all the forces, we had to think of the position of our weight, fins, and water. The position of our weight required common sense. We put it in the very front of the rocket ( basically the metal nut and the egg) so that the rocket did not wobble in the air. The center of gravity of the rocket would be more towards the front initial and in the end definitely in the front at the end of the path. For our fins, we needed to make sure that it was not to long or too short. This was so we could reduce the air resistance so the rocket could go farther. Lastly the water was a part of the physics for the rocket. If we put too much water, it would be too heavy and according to the equation of F=ma, more mass (more water) would create a bigger normal force and the rocket might fall faster causing the egg to break not go far enough. We eventually put in 

The Surviving Egg

      The material we sued was styrofoam. The properties in this material is a shock absorbing material. This means that it absorbs the force and it takes it in and does not affect the egg inside because of its properties. Also, the other reason why it protects the egg is due to how it is mostly made of air pockets.  

The Results

Mr. Zook with setting up our Rocket

        The final results was our egg staying alive and our rocket going 87 meters. Our angle was very low compared to many: 30 degrees. The reason we put it at this angle was due to the fact that at a lower degree, the rocket would have a softer impact and the egg survived. We used 550 mL because we just wanted our rocket to go to 30 meters, there was no expectation that it would fly 57 more than we thought we foresaw. Honestly nothing went wrong with our rocket; it flew perfectly fine in our case. However, if we did want it to go exactly 30, then we would need a lot more weight.

What Did I Learn?

        I learned that if you go through the simpler methods in this lab, there is less chance for error and failure.  Compared to others with parachutes, cones, yarn, and sand, our rocket was very simple with having a few things on it. Also I learned that styrofoam is very helpful for keeping things safe and protected without getting anything damaged. Also i learned about all the forces that are being applied to the rocket, and how the rocket gains speed and acceleration.