Overall, our bottle rocket experience was not only stressful, but also inventive, an opportunity to stretch our creativity through the practical application of science. We had our share of achievements and failures during the constructing process which began with only fins on February 28, 2011 at 2 - 3 seconds of flight time. That day, we had difficulty setting up our launching station because the relapse clip failed to attach to the launch pad. To save time we went to another station where we launched the ¼ filled H20 rocket.
Attempting to create a constant in our study, we filled the bottle to about ⅓ of it, realizing it maximizes the pressure inside when air is pumped into it. 50 psi powered our first launch, increasing to 80 psi by the end of the project: the increase in air pumped was directly related to the pressure inside the bottle, increasing distance traveled. By launch #3, we added rocks taped to the nose of the rocket to increase the center of mass, stabilizing it while in flight. We also added tabs at the top of the rocket to help the attached cone come off at apogee, allowing the parachute to deploy. According to Science Olympiad Student Center, the tabs help prevent the cone from getting stuck due to the opposing weight and friction in launch.
As we added modifications, our traveling time increased from 2 to 5 to 7 seconds. Our highest flight time was 9 seconds, however, on judgment day we made 6 seconds because we adjusted our parachute size and our cone broke, making us use the larger cone which disabled the tabs. Even though we didn’t make 10 seconds, we learn a lot through trial and error, realizing that you can never perfectly replicate something; hopefully one day, we will understand our rocket and exceed our goal of 10 seconds.
For the most part, it seems that by the end of this project we began to understand the science concepts behind this including thrust, weight, lift and drag. Thrust was created by the pressurized air in the rocket. Weight was created by the rocks that we taped on top of the rocket. Lift and drag are the opposing forces which act through the center of pressure. In class we learned that the center of mass should be above the center of pressure. We used more mass in opposition to thrust, which allowed the rocket to lift into the air. Drag was created by the smoothness of the rocket. Also, because of our duct tape adding more air friction, our rocket had drag. Overall we learned a lot through this project about physics concepts.
Sources
"Bottle Rocket - Science Olympiad Student Center Event Wiki." Scioly. Web. 11 Mar. 2011.
"Rocket Aerodynamic Forces." Space Flight Systems Directorate / Glenn Research Center. Web. 11 Mar. 2011.
Good job to your group! You're right about replicating the results. I'm sure it's possible for those that are highly skilled at it but making the rocket go up for 9 seconds every single time is a hard feat to accomplish. It's good that you got information from other sources besides just trial and error because sometimes other people might have a better outlook on things. Good job overall and if you guys do try again I hope everything goes well.
ReplyDeleteYou guys did a great job in your overall progression of flight times. Its great to see that you guys were able to continuously improve your rockets and that your flight times increased as a result. Your analytical investigation was quite interesting and it was good that you were able to adjust your rocket to different situations. As Joel said, the resources that you guys used were helpful due to the fact that there is always a chance for human error. Great job with your overall rocket.
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