The goal of this project was to create a projecting device that could send a projectile as far as possible. It had to have a base, two legs, an axle, and a lever with a load end and an effort end. It also had to be easily portable and had to fit in a 1x1x1 meter area. Our own design was a rubber band powered trebuchet. It had two 30.5 cm tall legs on a base, an arm with a 2:1 load to effort ratio, several rubber bands powering the trebuchet, a 12 gram clay ball on a 10 cm string, and a carpenter’s nail from which the ball flew. After conducting our own testing as well as looking at other groups testing, we made a few modifications.
CLEAR Paragraph
With our experiment, we concluded that the optimal nail angle for releasing a projectile off a trebuchet is 10° facing backwards. Our experiment consisted of firing our trebuchet, which used a nail with almost no head, which we changed the angle of as our independent variable. We then measured the distance that the trebuchet fired the projectile as our dependent variable. The only variable we changed was the nail angle, and we made sure it stayed that way. Our trebuchet had approximately a 2:1 load to effort ratio and we used a medium sized clay ball. We experimented with five different angle measurements and did three trials for each. Our angle measurements were 15° forward, 5° forward, 90°, 5° backward, 10° backward, and 15° backward. We found the average distance for each to be 9.5m, 12.2m, 11.12m, 13.7m, 14.4m, and 9.2m respectively. From the evidence, we can derive that 10° forward is the highest data point. This means that the optimum angle for launching a projectile the farthest with a trebuchet is 10° backward so far. When this data is graphed, we see that the relationship between nail angle and projectile distance can be modeled by a quartic function, with 10° forward and backward being the two highest points, 10° backward being slightly higher. Now we know for sure that 10° backward is the best nail angle to launch the projectile the farthest. This is because the optimum angle for launching a projectile in an air filled environment is 30°, and a 10° backward nail angle achieves this the best. In conclusion, if you want to launch a projectile the farthest, use a nail angled 10° backwards.
This was a very fun and interesting project to work on, I gained a much deeper understanding of projectile motion. We did very well in some areas. We did very well on testing our own variable and presenting that. I also feel that I did a good job on my proof of efficacy document and by identifying the perfect trebuchet. we could have improved our cooperation, leadership, and productivity, but in general, this was a very sucessful project.
CLEAR Paragraph
With our experiment, we concluded that the optimal nail angle for releasing a projectile off a trebuchet is 10° facing backwards. Our experiment consisted of firing our trebuchet, which used a nail with almost no head, which we changed the angle of as our independent variable. We then measured the distance that the trebuchet fired the projectile as our dependent variable. The only variable we changed was the nail angle, and we made sure it stayed that way. Our trebuchet had approximately a 2:1 load to effort ratio and we used a medium sized clay ball. We experimented with five different angle measurements and did three trials for each. Our angle measurements were 15° forward, 5° forward, 90°, 5° backward, 10° backward, and 15° backward. We found the average distance for each to be 9.5m, 12.2m, 11.12m, 13.7m, 14.4m, and 9.2m respectively. From the evidence, we can derive that 10° forward is the highest data point. This means that the optimum angle for launching a projectile the farthest with a trebuchet is 10° backward so far. When this data is graphed, we see that the relationship between nail angle and projectile distance can be modeled by a quartic function, with 10° forward and backward being the two highest points, 10° backward being slightly higher. Now we know for sure that 10° backward is the best nail angle to launch the projectile the farthest. This is because the optimum angle for launching a projectile in an air filled environment is 30°, and a 10° backward nail angle achieves this the best. In conclusion, if you want to launch a projectile the farthest, use a nail angled 10° backwards.
- Trebuchet power- our next modification that we made was to increase the number of rubber bands used to power the trebuchet as well as switching from single rubber bands to double rubber bands tied together. This made the trebuchet swing faster, which gave the ball more velocity.
- Trebuchet arm length- next, we cut our trebuchet arm to give it a load to effort ratio of 3:2 instead of 2:1. This made the arm lighter, so it could be accelerated faster by the rubber bands and lets the arm have a proper follow-through.
- Projectile modifications- then, we modified our ball to be seven grams and be attached with a 20 cm string. This made the projectile light enough to travel far but heavy enough not to slow down because of air resistance.
This was a very fun and interesting project to work on, I gained a much deeper understanding of projectile motion. We did very well in some areas. We did very well on testing our own variable and presenting that. I also feel that I did a good job on my proof of efficacy document and by identifying the perfect trebuchet. we could have improved our cooperation, leadership, and productivity, but in general, this was a very sucessful project.