Bungee Drop C

[chinesesushi]

As in, at which point do they attach the cord to the wall (or stairwell etc)?

Measuring from the bottom of the key ring which is at the bottom of the cord, 1 meter up is will they will attach it to wherever they're attaching it too.

[blindmewithscience]

Exactly how much theoretical calculantions are you guys doing for this competition? Our team has derived an equation for the length of the cord with a given height and mass, and we're using that to estimate our drops (which so far is somewhat accurate).
Also, how many tests with your cord have you done so far/plan to do before the competition?

[sciolymom]

When measuring the drop height, is the height measured from the top edge of where the cord is attached on the drop mechanism?

Hope I am asking this in a way that makes sense.... if you look at the pictures in the gallery for example. The cord is attached with a clamp and then goes over the edge of the 2x4. Is the top of the 2x4 where the drop height is measured? The release mechanism height has no affect on this, is that correct?

Thank you!

[bernard]

An FAQ was posted for this question on the official Science Olympiad website.

What is the definition of "drop height?"is it the bottom of the plastic bottle? The top? the top including all attached pieces by the event supervisors?The height of the anchoring system's top of ledge? (section: 3 / paragraph: b / line: 1)
The drop height is measured from the bottom of the bottle.

[sciolymom]

??? Ok....so our device ends at the key ring. The supervisor can use whatever they choose to attach the bottle to the key ring. They could have, for example, an o ring plus a carbiner, or maybe just an o-ring, or even some duct tape plus a carbiner. All of that could change the height of "the bottle". Also, the dropping mechanism could be totally different from what we are testing with. For example...our cord attaches to the ledge. Our release mechanism is a little bit above that, which would determine where the "bottom of the bottle" ends up. If the drop mechanism is different at the competition, that could change the distance between the cord attachment and the bottom of the bottle.

Am I not understanding this right, or does that not make it impossible to test accurately?

[bernard]

Please see rule 2.c., which states that the bottle's mass and length, including the attachment mechanism, will be announced after impound. Also per rule 2.c., the "top anchoring system" holds onto the "attachment mechanism," making the distance from the bottom of the bottle to the landing surface the same for all cords regardless of the size of metal ring (described in 2.a.) used by teams.

[sciolymom]

Please see rule 2.c., which states that the bottle's mass and length, including the attachment mechanism, will be announced after impound. Also per rule 2.c., the "top anchoring system" holds onto the "attachment mechanism," making the distance from the bottom of the bottle to the landing surface the same for all cords regardless of the size of metal ring (described in 2.a.) used by teams.

Thank you for responding!

[reedm121]

I'm new to science olympiad this year so i'm a bit confused. Do I construct a cord and control its length based upon the mass and height at the time of the event?

[bernard]

I'm new to science olympiad this year so i'm a bit confused. Do I construct a cord and control its length based upon the mass and height at the time of the event?

Yes.

[reedm121]

so I should find the spring constant (k) before hand with trials and such and then during the competition plug in the F value (which I could calculate from the mass) into the equation F=kx to find x, which I could use to determine the height?
Also is it okay that I made my "bungee" out of rubber bands?