Bungee Drop C

[joiemoie]

Note you are assuming there is a non-elastic portion of the cord. I've seen many devices that are completely elastic.

In addition, there are many advantages to having an all-elastic cord.
1-It wears out slower than cords with a non-elastic portion, as it slows it down over a longer period of time and a longer distance.
2-The mass slowing down over a longer period of time can help you score higher. How? Suppose that a camera were videoing 2 cords that both got to 5cm above the ground, with one fully elastic and the other only partially elastic. The partially elastic cord is accelerating much faster at the bottom than the fully elastic one. If you look at the video of the partially elastic cord, there will be a lot of change from frame to frame, and so the very bottom probably won't be caught on camera. However, the video of the fully elastic one will accelerate slower at the bottom, and so you can more easily see the bottom on camera.

I'm not exactly sure about your first advantage, however the second reason is completely valid. However, I think that issue is mostly a concern with how accurate event directors are willing to go, and i think that at nationals, accuracy in measuring should not be a concern (they might also use those sensors that can also accurate tell distance, at which framerate doesn't even come into play).

The main advantage with a partially elastic bungee is that the equations are
1) Much easier to work with since you're working with a constant "k" value.
2) An entire length bungee would have to take into account k values at various lengths along the cord, something not easy to do. (I checked to see if it followed a y=kx or yx=k type relationship and neither worked) Equations modeling k values for elastics stretching at different points are very difficult to find and specific, and creating an experimental equation for k values at different locations give lots of room for error.

[chinesesushi]

IMO, at nationals last year, Bungee Drop was run worse than at the MIT invitational this year. It was also run worse than an invitational that I attended at my school. The event supervisor was not to particular in their measurements, to say the least. It would be fantastic if the guy who ran it at MIT invitational also ran it at nationals this year, because the system they had was quite good and worked well. He also happened to volunteer at nationals last year XD.

[joiemoie]

IMO, at nationals last year, Bungee Drop was run worse than at the MIT invitational this year. It was also run worse than an invitational that I attended at my school. The event supervisor was not to particular in their measurements, to say the least. It would be fantastic if the guy who ran it at MIT invitational also ran it at nationals this year, because the system they had was quite good and worked well. He also happened to volunteer at nationals last year XD.

Really? I was at the MIT invitationals this year, and i must say, that was probably worse administration than i had seen than in even regionals. I was part of block 1, where all the issues occurred. First the mass was recorded to be 306 grams (already going past specifications) then changed to 297 grams (suggesting inaccuracy in equipment). Next, they used a laser to measure drop height, ended up measuring incorrectly (4.31m but in reality 3.81m) and had to request teams that tiered to come back another block and try again. They had to redo all the measurements on the spot using rather imprecise ruler measurements. Next, they used carabiners (which they even admitted later should have probably used clamps since many teams unfairly had their bungees slip off due to poor attachment to carabiner. also they are just overall worse than clamps). Finally, even the top placing MIT scores were worse than usual, even with teams from top national schools such as troy. 50 cm very poor, especially when the yale top placing scores were about 2cm. The fact that even normally solid teams did this poorly suggested a problem with the overall event. Also, they put one team from our school in tier 6 by accident and gave it 39th place. It passed the elasticity test. It did not hit the ground on either drop. It was impounded. Had our team not experienced the false tier, it wouldve given us enough points to surpass troy high school for 3rd :'( oh well

Also all of these problems were sent to the MIT Science Olympiad director, and as quoted "Regardless, please rest assured that we treat these possible issues gravely seriously, and we have thoroughly addressed the items you mention with our Bungee Drop event supervisor, who will not be invited to supervise events at any Science Olympiad at MIT tournament in the future. It is particularly embarrassing to me that these problems arose with Bungee Drop, given the care with which we vetted and selected our event supervisors, and especially because our Bungee Drop event supervisor has been intimately involved with planning and running the event at the national tournament."

[chinesesushi]

IMO, at nationals last year, Bungee Drop was run worse than at the MIT invitational this year. It was also run worse than an invitational that I attended at my school. The event supervisor was not to particular in their measurements, to say the least. It would be fantastic if the guy who ran it at MIT invitational also ran it at nationals this year, because the system they had was quite good and worked well. He also happened to volunteer at nationals last year XD.

Really? I was at the MIT invitationals this year, and i must say, that was probably worse administration than i had seen than in even regionals. I was part of block 1, where all the issues occurred. First the mass was recorded to be 306 grams (already going past specifications) then changed to 297 grams (suggesting inaccuracy in equipment). Next, they used a laser to measure drop height, ended up measuring incorrectly (4.31m but in reality 3.81m) and had to request teams that tiered to come back another block and try again. They had to redo all the measurements on the spot using rather imprecise ruler measurements. Next, they used carabiners (which they even admitted later should have probably used clamps since many teams unfairly had their bungees slip off due to poor attachment to carabiner. also they are just overall worse than clamps). Finally, even the top placing MIT scores were worse than usual, even with teams from top national schools such as troy. 50 cm very poor, especially when the yale top placing scores were about 2cm. The fact that even normally solid teams did this poorly suggested a problem with the overall event. Also, they put one team from our school in tier 6 by accident and gave it 39th place. It passed the elasticity test. It did not hit the ground on either drop. It was impounded. Had our team not experienced the false tier, it wouldve given us enough points to surpass troy high school for 3rd :'( oh well

Also all of these problems were sent to the MIT Science Olympiad director, and as quoted "Regardless, please rest assured that we treat these possible issues gravely seriously, and we have thoroughly addressed the items you mention with our Bungee Drop event supervisor, who will not be invited to supervise events at any Science Olympiad at MIT tournament in the future. It is particularly embarrassing to me that these problems arose with Bungee Drop, given the care with which we vetted and selected our event supervisors, and especially because our Bungee Drop event supervisor has been intimately involved with planning and running the event at the national tournament."

Ehh I guess they had resolved all their issues by the time our team went. Troy screwed up in Bungee lol, 50 cm is very poor XD. Yeah idk I guess when I saw it run they looked pretty accurate and well-run, I'm sorry you had those issues how was your actual score without the tiering and such?

[joiemoie]

IMO, at nationals last year, Bungee Drop was run worse than at the MIT invitational this year. It was also run worse than an invitational that I attended at my school. The event supervisor was not to particular in their measurements, to say the least. It would be fantastic if the guy who ran it at MIT invitational also ran it at nationals this year, because the system they had was quite good and worked well. He also happened to volunteer at nationals last year XD.

Really? I was at the MIT invitationals this year, and i must say, that was probably worse administration than i had seen than in even regionals. I was part of block 1, where all the issues occurred. First the mass was recorded to be 306 grams (already going past specifications) then changed to 297 grams (suggesting inaccuracy in equipment). Next, they used a laser to measure drop height, ended up measuring incorrectly (4.31m but in reality 3.81m) and had to request teams that tiered to come back another block and try again. They had to redo all the measurements on the spot using rather imprecise ruler measurements. Next, they used carabiners (which they even admitted later should have probably used clamps since many teams unfairly had their bungees slip off due to poor attachment to carabiner. also they are just overall worse than clamps). Finally, even the top placing MIT scores were worse than usual, even with teams from top national schools such as troy. 50 cm very poor, especially when the yale top placing scores were about 2cm. The fact that even normally solid teams did this poorly suggested a problem with the overall event. Also, they put one team from our school in tier 6 by accident and gave it 39th place. It passed the elasticity test. It did not hit the ground on either drop. It was impounded. Had our team not experienced the false tier, it wouldve given us enough points to surpass troy high school for 3rd :'( oh well

Also all of these problems were sent to the MIT Science Olympiad director, and as quoted "Regardless, please rest assured that we treat these possible issues gravely seriously, and we have thoroughly addressed the items you mention with our Bungee Drop event supervisor, who will not be invited to supervise events at any Science Olympiad at MIT tournament in the future. It is particularly embarrassing to me that these problems arose with Bungee Drop, given the care with which we vetted and selected our event supervisors, and especially because our Bungee Drop event supervisor has been intimately involved with planning and running the event at the national tournament."

Ehh I guess they had resolved all their issues by the time our team went. Troy screwed up in Bungee lol, 50 cm is very poor XD. Yeah idk I guess when I saw it run they looked pretty accurate and well-run, I'm sorry you had those issues how was your actual score without the tiering and such?

With the inaccuracies, about 50ish cm. However, when we tested at the previous tournament, yale, and also regionals, we got 6cm for yale and 2cm for regionals. At least you had a good experience

[TheLeftEye]

What do you guys think a good range for safety is at a competition? We use like 8 cm since temperature and stuff like that can affect everything. Also, we are using springs and we are getting really good results, but I have not seen a single team other than us use them. Any ideas why springs are bad?

[blindmewithscience]

I think that springs are generally not used beacuse
1) The chance of tangling on the way down is significantly higher for springs than other types of elastic cords
2) In section 3c, the elasticity test states "while being suspended vertically, the bottom meter of the cord must stretch to at least 1.25 meters when a single 500 g mass is attached to this section and return to within 5cm of its original length after the mass is removed." With many springs, they can stretch out because of their own weight, and won't return to their original length.

[FlyingMonkey85]

Does anyone remember what the combined drop distances were like for the medaling teams at nationals last year?

[chinesesushi]

Does anyone remember what the combined drop distances were like for the medaling teams at nationals last year?

I think first was like 4 centimeters, not sure though.

[DKluver]

So I built the measurement tool for bungee drop but I am not sure how to calibrate the device and what the final setup should look like. Any help would be great.