My experience with the trebuchet challenge project was very positive! I thoroughly enjoyed the experience. Specific things that went well for my team and myself were:
1. Teamwork: My team members are good friends of mine. This made it easy to work with other group members. This also enabled us to be very comfortable to share ideas and opinions about our trebuchet and the experience. Also, we were easily available to work together on the trebuchet in order to complete it.
2. Test Day: Test day went very well for my team. This really encouraged us and gave us motivation as we moved from test day to competition day.
3. Distance Competition: Our distance competition was very successful! We were able to achieve hurls of over 50.0 m every time with our trebuchet. We were thrilled with these results!
4. Paper Trebuchet Construction: Our paper trebuchet was constructed very quickly. This was mainly due to the fact that all of the members in my group had spares at the same time and were able to all contribute to the construction of the mini paper trebuchet.
One of the recommendations that I have for future physics 40S students for the trebuchet challenge would be to research trebuchets. Look in to how successful trebuchets have been constructed and engineered! Also, I would recommend trying a variety of pouches for the trebuchet itself. The pouch is such a crucial aspect of the trebuchet that getting the perfect pouch may make or break your entire trebuchet. A final recommendation that I have for future physics students is to not change things that work well- especially the day before, or during competition day. If you have your trebuchet hurling over 25m consistently, leave it! Don't change everything to try to drastically increase your distance because it may cause your trebuchet to have less than optimal results.
Wednesday, May 25, 2011
Trebuchet Challenge Competition Reflection
Our trebuchet performed very well in the accuracy part of the challenge! Our best hurl of the tennis ball landed 0.620 m from the center of the hula hoop- we were thrilled with these results! As a result of our success, we were awarded 2nd place in the accuracy competition and received 9/10 points!
If I had the opportunity to modify our current trebuchet, I would make it better suited for the accuracy competition. Although our bungee cords worked well in the accuracy competition, I feel that adjusting the counterweight mass may have been a better and more precise way to control the distance the tennis ball flew. The bungee cords reduced the speed at which the arm fell, reducing the velocity with which the ball was released. I feel that if we had adjusted the weight, we would have been able to more accurately adjust the range (through using different masses of weights) that our tennis ball flew.
I feel that our overall design of the trebuchet was quite excellent. If we were to create a completely new trebuchet, I think we may have used a slightly larger counterweight, which would have hopefully caused the tennis ball to fly further, improving our distance competition results.
Toward the end of the distance competition, the sewing on our pouch became loose. I feel that if we had reinforced the sewing on the pouch that the trebuchet may have performed better. Also, we could have tweaked the angle of release slightly by adjusting our nail. We did not adjust the nail however, because we felt that we had a good angle of release and chose not to alter something that had worked consistently well for us.
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| Our loaded trebuchet for the accuracy competition- ready to fire! |
If I had the opportunity to modify our current trebuchet, I would make it better suited for the accuracy competition. Although our bungee cords worked well in the accuracy competition, I feel that adjusting the counterweight mass may have been a better and more precise way to control the distance the tennis ball flew. The bungee cords reduced the speed at which the arm fell, reducing the velocity with which the ball was released. I feel that if we had adjusted the weight, we would have been able to more accurately adjust the range (through using different masses of weights) that our tennis ball flew.
I feel that our overall design of the trebuchet was quite excellent. If we were to create a completely new trebuchet, I think we may have used a slightly larger counterweight, which would have hopefully caused the tennis ball to fly further, improving our distance competition results.
Toward the end of the distance competition, the sewing on our pouch became loose. I feel that if we had reinforced the sewing on the pouch that the trebuchet may have performed better. Also, we could have tweaked the angle of release slightly by adjusting our nail. We did not adjust the nail however, because we felt that we had a good angle of release and chose not to alter something that had worked consistently well for us.
Friday, May 20, 2011
Competition Day Reflection
Our trebuchet had great results in the distance part of the competition. Our trebuchet had the greatest distance results! It had an average distance of 51.22 m. Our greatest distance achieved was 52.11 m.! We were very pleased with the results.
To make our trebuchet meet the challenges posed by the accuracy component of the competition we are going to shorten our trebuchet throwing arm and add bungee cords to the design. The bungee cords with slow down the fall of the counterweight, which will shorten the distance thrown. We are also going to reinforce the pouch to make it more durable for further trials.
To make our trebuchet meet the challenges posed by the accuracy component of the competition we are going to shorten our trebuchet throwing arm and add bungee cords to the design. The bungee cords with slow down the fall of the counterweight, which will shorten the distance thrown. We are also going to reinforce the pouch to make it more durable for further trials.
Theoretical Range and Competition Day
Range = 2 x h x (M/m)
Range = 2 x 33 cm x (22.6796 kg / 0.057 kg)
Range = 26260.59 cm
Range = 262.6 m
Average distance= (51.69m + 50.99m + 42.11m + 50.29m + 51.00m) / 5
Average distance= 51.22 m
Difference between Range and Average distance= 262.6m - 51.22m
Difference between Range and Average distance= 211.38m
Five reasons that kept us from achieving the performance suggested by the theoretical range:
1. Release Angle: The release angle of our trebuchet although close to 45 degrees, was not precisely 45 degrees. As a result our distance was not totally optimized by the design of our trebuchet.
2. Air resistance: Air resistance is completely ignored within the theoretical range of the trebuchet. Air resistance however had enormous effects on the flight of our tennis ball.Air resistance opposed the motion of the ball while in flight.
3. Release Mechanism Issues: Our pouch and release mechanism was not perfected. As a result the theoretical range of the trebuchet was not realized due to issues with release point and mechanism. The pouch was not perfected. There were issues with the ball being release at exactly the right point in time.
4. Friction: There was friction that existed between the mechanical parts of the trebuchet. These values were ignored in the calculations of the range. The friction would have hindered the results of the trebuchet.
5. Air resistance of the tennis ball: A tennis ball was not the ideal object to be thrown by a trebuchet. The textured edges of the tennis ball created excess air resistance between the tennis ball fuzz and the air.
Range = 2 x 33 cm x (22.6796 kg / 0.057 kg)
Range = 26260.59 cm
Range = 262.6 m
Average distance= (51.69m + 50.99m + 42.11m + 50.29m + 51.00m) / 5
Average distance= 51.22 m
Difference between Range and Average distance= 262.6m - 51.22m
Difference between Range and Average distance= 211.38m
Five reasons that kept us from achieving the performance suggested by the theoretical range:
1. Release Angle: The release angle of our trebuchet although close to 45 degrees, was not precisely 45 degrees. As a result our distance was not totally optimized by the design of our trebuchet.
2. Air resistance: Air resistance is completely ignored within the theoretical range of the trebuchet. Air resistance however had enormous effects on the flight of our tennis ball.Air resistance opposed the motion of the ball while in flight.
3. Release Mechanism Issues: Our pouch and release mechanism was not perfected. As a result the theoretical range of the trebuchet was not realized due to issues with release point and mechanism. The pouch was not perfected. There were issues with the ball being release at exactly the right point in time.
4. Friction: There was friction that existed between the mechanical parts of the trebuchet. These values were ignored in the calculations of the range. The friction would have hindered the results of the trebuchet.
5. Air resistance of the tennis ball: A tennis ball was not the ideal object to be thrown by a trebuchet. The textured edges of the tennis ball created excess air resistance between the tennis ball fuzz and the air.
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| Our trebuchet loaded and ready to go for the distance competition on competition day! |
Wednesday, May 18, 2011
Trebuchet Challenge Test Day
Our trebuchet challenge test day was very successful! Our trebuchet had many successful trials. Our best trial achieved a distance of 60 m! We were very pleased. A probable factor that aided our success was having a strong wind at our backs which helped our tennis ball fly very far. Hopefully we have the wind on our side on challenge day!
On test day, we had not made adjustments to alter our trebuchet for the accuracy competition. However, thoughout the week we worked on our trebuchet and came up with a system that reduced the distance that the trebuchet hurled the ball by decreasing the speed and the distance with which the counterweight fell.
Throughout the process of making our trebuchet, we had to remake a pouch. Our pouch design, though simple, works very well. It is made of lightweight cotton, and ribbon. Hopefully it is durable enough to last for test day!
Below is a video of our trebuchet in action!
On test day, we had not made adjustments to alter our trebuchet for the accuracy competition. However, thoughout the week we worked on our trebuchet and came up with a system that reduced the distance that the trebuchet hurled the ball by decreasing the speed and the distance with which the counterweight fell.
Throughout the process of making our trebuchet, we had to remake a pouch. Our pouch design, though simple, works very well. It is made of lightweight cotton, and ribbon. Hopefully it is durable enough to last for test day!
Below is a video of our trebuchet in action!
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| Our trebuchet on test day! |
Wednesday, May 4, 2011
Trebuchet Challenge Project Post #1
Creating our paper trebuchet was fun and a true learning experience! We created our trebuchet, at it successfully achieved both the distance and accuracy requirements.
Creating the paper trebuchet was relatively easy. There was some slight frustration with the cutting and folding at the start. It was somewhat difficult to know which lines to cut, which lines to fold up, and which lines to fold down. It was also relatively difficult to create an appropriate pouch. It was difficult to create a pouch that held the ball tight enough so that it would not fall out, but not too tight as to prevent the ball from being released.
Air resistance was relatively minimal in operating our paper trebuchet. Air resistance was hard to recognize and did not have a recognizable effect on the flight of our ball. We can, however, know that there was air resistance present.
Gravity played a huge role in our operating our trebuchet. We had to work with gravity to create a trebuchet that released the ball at a point that would created optimal results in both distance and accuracy.
The angle of release on our trebuchet was 45 degrees. This truly optimized the distance our trebuchet hurled the ball. When the angle of release is 45 degrees, a specific relationship exists between the x and y components that shows optimal results in hurling distance.
The counterweight we used for the distance competition was very large. We used approximately 40 individual weights to optimize our distance. When we were concerned with accuracy, we decreased the number of weights weights to 25 weight, which reduced the distance that the ball would go, without compromising the angle of release.
Creating the paper trebuchet was relatively easy. There was some slight frustration with the cutting and folding at the start. It was somewhat difficult to know which lines to cut, which lines to fold up, and which lines to fold down. It was also relatively difficult to create an appropriate pouch. It was difficult to create a pouch that held the ball tight enough so that it would not fall out, but not too tight as to prevent the ball from being released.
Air resistance was relatively minimal in operating our paper trebuchet. Air resistance was hard to recognize and did not have a recognizable effect on the flight of our ball. We can, however, know that there was air resistance present.
Gravity played a huge role in our operating our trebuchet. We had to work with gravity to create a trebuchet that released the ball at a point that would created optimal results in both distance and accuracy.
The angle of release on our trebuchet was 45 degrees. This truly optimized the distance our trebuchet hurled the ball. When the angle of release is 45 degrees, a specific relationship exists between the x and y components that shows optimal results in hurling distance.
The counterweight we used for the distance competition was very large. We used approximately 40 individual weights to optimize our distance. When we were concerned with accuracy, we decreased the number of weights weights to 25 weight, which reduced the distance that the ball would go, without compromising the angle of release.
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| The trebuchet and myself! |
Tuesday, April 5, 2011
Spring Break Physics
Over spring break, I went to Europe! I encountered numerous applications of physics throughout my trip. One application was the airplane that we took to fly to Paris. An unbelievable amount of work was done in the plane's flight. The tires of the plane encountered friction with the runway as it gained velocity in order to take flight. The plane's engines worked hard in order to help the plane achieve a velocity of approximately 600 mph. The plane while in the air had to maintain velocity and create a force great enough to oppose the force of gravity acting on the massive aircraft.There was a massive force opposing the force of gravity, enabling the plane to fly at an extremely high altitude. Also, while in flight and taking off, the plane encountered air resistance. The plane was designed in a streamline matter to keep the air resistance to a minimum.
Monday, March 14, 2011
Nuclear Physics Challenge Project
My team is doing our Nuclear Physics Challenge Project on Radiation Therapy.
I will complete the report, with Luke and Ellisha adding their ideas into the report. We all helped proofread and make appropriate adjustments to make the report more powerful.
Ellisha is finding the important points within our report to make the fact sheet, which will highlight the main points demonstrated within both our report and PowerPoint.
Luke will create the PowerPoint, with help from Ellisha and myself. The PowerPoint will be based on the report we created on Radiation therapy. We will discuss together the specific information that we wish to include in our PowerPoint, and will discuss the specific visuals and videos that will be included as well.
Our demonstration/activity will be a collaborative effort, with all of our ideas being considered in creating a powerful and appropriate demonstration. We will all participate in the presentation.
I will complete the report, with Luke and Ellisha adding their ideas into the report. We all helped proofread and make appropriate adjustments to make the report more powerful.
Ellisha is finding the important points within our report to make the fact sheet, which will highlight the main points demonstrated within both our report and PowerPoint.
Luke will create the PowerPoint, with help from Ellisha and myself. The PowerPoint will be based on the report we created on Radiation therapy. We will discuss together the specific information that we wish to include in our PowerPoint, and will discuss the specific visuals and videos that will be included as well.
Our demonstration/activity will be a collaborative effort, with all of our ideas being considered in creating a powerful and appropriate demonstration. We will all participate in the presentation.
Thursday, February 24, 2011
Egg Drop Challenge Project: Competition Day!
Yesterday we had our final competition day for our Egg Drop Challenge project. The container created by my partner and myself had an official final mass of 321.10 g, with dimensions of 24 cm x 24 cm x 24 cm. Our egg drop container took 0.94 seconds to complete the 5 m fall. Once our egg has landed we found out it survived- with the shell completely intact! As a result of our container's relatively high mass, our container received a score of 62.29 for its earned egg points.
I felt that the most limiting restriction during the design phase of my container was the size dimension restriction. My group chose to incorporate an elastic band suspension system into our container. We felt that to optimize our suspension system, a container as large as possible would be best. A large container would provide ample space for the suspended egg container (the smaller internal container) to move around in, without colliding with the ground or the external container. A large external container would provide a large amount of space for the inner container to be suspended within, preventing a great amount of collisions with the external container, due to the increased space between the two containers. Due to the 25 cm x 25 cm x 25 cm dimension limitation, we had to overcome the restriction that our container could not be as large as possible.
The most effective part of our design was the suspension system itself. We chose to incorporate the suspension system into our design because we knew it would reduce the impact of the force on the egg when our container hit the floor. The suspension system prevented the small internal egg container from hitting the ground and the larger external container. When the container hit the floor the small suspended egg container did not come in contact with any surface, and simply bobbed up and down, suspended by the stretchy elastics. This greatly reduced any impact experienced on the egg when the container hit the floor.
The least effective part of our container's design was the material we chose to create our container out of. We chose to use a relatively dense and heavy cardboard to make our container. If we had chosen to use a lighter cardboard, plastic or styrofoam, we not only would have increased our earned egg points, but it is probable that the container would have fallen less quickly, due to it's reduced mass. A slower fall time would have likely reduced the force with which the container came in contact with the floor, reducing the forces on the egg, that have the potential to cause it to break.
In order adapt our container to safely carry two raw eggs I would add an small box adjacent to the small box suspended within the large external container. This would take the basic principles of our original container and apply them to carrying two raw eggs. The only significant adjustments that would be needed would be to adjust the tension of the suspension elastics (because the two square based containers would combine to create a rectangle based container). To achieve these tension differences, my group would have to investigate the proper tension for the two different side lengths, in order to make both eggs survive and for the suspension system to work as it is intended to.
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| High anxiety on Competition day! |
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| Nick with our egg! Sweet success! |
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| A view of the inside of our egg drop container. The egg was contained within the inner container. |
The most effective part of our design was the suspension system itself. We chose to incorporate the suspension system into our design because we knew it would reduce the impact of the force on the egg when our container hit the floor. The suspension system prevented the small internal egg container from hitting the ground and the larger external container. When the container hit the floor the small suspended egg container did not come in contact with any surface, and simply bobbed up and down, suspended by the stretchy elastics. This greatly reduced any impact experienced on the egg when the container hit the floor.
The least effective part of our container's design was the material we chose to create our container out of. We chose to use a relatively dense and heavy cardboard to make our container. If we had chosen to use a lighter cardboard, plastic or styrofoam, we not only would have increased our earned egg points, but it is probable that the container would have fallen less quickly, due to it's reduced mass. A slower fall time would have likely reduced the force with which the container came in contact with the floor, reducing the forces on the egg, that have the potential to cause it to break.
In order adapt our container to safely carry two raw eggs I would add an small box adjacent to the small box suspended within the large external container. This would take the basic principles of our original container and apply them to carrying two raw eggs. The only significant adjustments that would be needed would be to adjust the tension of the suspension elastics (because the two square based containers would combine to create a rectangle based container). To achieve these tension differences, my group would have to investigate the proper tension for the two different side lengths, in order to make both eggs survive and for the suspension system to work as it is intended to.
Wednesday, February 16, 2011
Egg Drop Challenge: Test Day
Today in physics we had a period to test our egg drop vehicles, and make and record any adjustments that were needed to ensure their success. My group encountered some minor obstacles. Originally our vehicle exceeded the maximum dimensions. However, the changes to make it obey the maximum dimensions were relatively minor and easy. We had to adjust the width of one side, as well as adjust the dimensions of the lid for our box. We made the adjustments and our vehicle now has the dimensions: 24 cm x 24 cm x 24 cm. We also encountered a bit of difficulty when an egg without a plastic bag was tested. The egg survived, however as it was removed it crumbled under the pressure of my partner's hand. As a result the existing cushioning materials (foam brush pads) were ruined. We were forced to replace the foam brush padding with gauze. However, when we tried the gauze the egg did not withstand two of our 5 m drops. As a result we experimented with bubble wrap, which worked just as well as the foam pads. Once we had secured our bubble wrap our vehicle operated consistently. Hopefully Murphy's Law won't interfere on competition day!
Thursday, February 10, 2011
Physics 40S Post #2
At the start of physics class today we watched another video called "Think Before You Post". The video focused on how important it is to monitor and control the images that you choose to post on the internet. We then added a ClustrMaps gadget to our blogs. Next, we adjusted the personal settings of our blogs. We changed our settings so that they were appropriate for our physics blog purposes. At the end of the class we explored how to comment on blogs, and were encouraged to comment on one anothers blogs.
Wednesday, February 9, 2011
40S Physics
Today we viewed a video about Internet safety called "Think Before You Post" and we discussed the importance of carefully choosing what we post on the Internet. We then experimented with adding gadgets to our blog, and were given time to add and remove different gadgets. We also were introduced to following other blogs, and were given time to follow the other students in 40S physics, as well as the VCI Science page.
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