Sara Beth’s Balloon-Powered Car Project

1. Sara Beth’s Balloon-Powered Car Project Star Of The Sea Mrs. Mitchell Science 10 March 2013

2. Rules The car must be powered by no more than 2 balloons. The car must have the same 3" x 6" foam core rectangle base we used in class. The car must have at least three wheels. The wheels can not be wheels from a toy car. They must be made out of something that was not originally meant to be used as wheels. The car must only be powered by the balloon(s) and not be assisted by any other outside force.

3. Rubric 1. Has a photo of your car on your wiki that shows how your new design used the same 3" x 6" foam core rectangle base we used in class but was altered in some other way from the original design. (5 points) 2. Has a neatly drawn and labeled blueprint uploaded to your wiki. (5 points) 3. Has a data table on your wiki with a least 5 runs showing the distance the car traveled, the time it took to travel it, and the speed the car achieved for each run. (5 points) 4. Has a bar graph on your wiki that matches the data in your table. Use the graph generator found at Create-A-Graph. (5 points) 5. Has a written analysis of your results posted on your wiki. In other words, why does your new car design allow it to travel further or faster than the original design created in class. This must be written as a paragraph of at least 5 sentences in length without spelling or grammatical errors and includes solid scientific principals in your explanation. (10 points) 6. Bonus: Post a video of your car on your wiki proving that it can travel at least 5 meters. (20 extra credit points)

4. Rubric 1: Proof of 3”x6” Original Base provided in Class My Father and I took these photos of my car on an 8 ½” by 11“ sheet of paper and with a ruler in frame for secondary scale reference. We found the length of the provided base was approximately 6 inches, +- 1/8 “. We found the width was approximately 3 inches, +- ¼ “. Nerf Disks were Frisbees not wheels

5. Rubric 1 (continued): Original Design Proof We added 4 large diameter straws to keep wheels from rubbing on body of the car. We added foam guides to keep the balloon from interfering with wheels during operation. We added a larger diameter straw to the exhaust port of the balloon, but decided this did not meet the original idea requirement. The larger straw increased our performance by 97% when comparing maximum speed attained in school trial to home trial. The wheels are from a Nerf disk shooter. We glued 2 disks together using super glue. Two disks glued together provided a more stable axle wheel interface.

6. Rubric 2: Neatly Drawn Blue Print Design from Internet Example The main differences of my design to that of the example design: The straw is straight not bendable for increased efficiency The wheelbase is wider for more stability The second straw keeps the wheels away from the body reducing friction The larger diameter straw provided greater thrust. Sara Beth’s Balloon-Powered Car Design

7. Rubric 3: Balloon-Powered Car Data Table Home Trial

8. Balloon-Powered Car Data Table School Trial

9. Rubric 4: Copy of home trial data provided 4. Has a bar graph on your wiki that matches the data in your table. Use the graph generator found at Create-A-Graph. (5 points) Screen capture from Create-A-Graph

10. Rubric 5: Written Analysis Star of the Sea Sara Beth Joyner #8 March 10 2013 Balloon-Powered Car I modified the design of my Balloon-Powered Car from the design given as an example for this project. My design goes further and faster when compared to the car made in class. The original design worked, but I found it unstable and underpowered. The instability came from design flaws. These design flaws included: wheels that wobbled, the balloon would fall and get caught up under the wheels, and the wheels were able to come into contact with the foam board. I first improved the wheels. By putting two disks together with glue and drilling holes into the center, I kept the wheel from wobbling and made the rotation more efficient. This allowed the car to track in a straighter line allowing the thrust to contribute to the cars speed in one direction. When the balloon was starting to deflate, it would often flop over and get under the wheels. I added vertical guides to keep this from happening by containing the balloon on the foam board. The car was not tracking in a straight line, so I increased the wheelbase and aligned the axles. I was not allowed to increase the size of the foam board, and I needed to keep the wheels from sliding too much so I added large straws as standoffs to help keep the wheel from getting too close to the foam board. When the wheels were allowed to touch the foam board, it created friction that slowed the car down. While not a design flaw, the straw we used in class was narrower then the one I used in my design. I increased the speed and distance of the car by using a larger balloon and a wider straw. The larger balloon would store more energy in the form of pressure and volume. The wider straw allowed greater amounts of air to be released allowing for greater power delivery to the system. Greater power delivery on a more stable platform allowed for the measured 97% increase in speed attained and distance traveled.The car would travel much faster as the balloon neared the deflated state so run five shows the performance of speed increasing when starting with a partially inflated balloon.

11. Rubric 6: Video Proof posted to Wiki of 5M performance Sara Beths Balloon-Powered Car Video http://www.youtube.com/watch?v=NQAysAUdkc4&feature=youtu.be Tape measure did not provide any necessary outside force. It did make some contact during the video, but the force was deemed insignificant. I do acknowledge the tape did exert lateral force on the system during the taping.