egg drop

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egg drop

Postby bstreeter » Mon Dec 08, 2008 4:42 pm

HELP! I am frustrated...... I have to make a contraption for an egg for an "egg drop".. I can only use masking tape and plastic straw... we are going to drop a raw egg from the bleachers. i have tried to make a design of my own ... but the eggs keep breaking when dropped. i have searched several sites and have no luck in a design. I need to have a design using these materials .. the project is due tomorrow. I have been trying to get onto your site for 2 days now.. PLEASE Help me if you can... i need an answer fast... Thank you

Nicole streeter
bstreeter
 
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Project Question: we are trying to do an experiment dealing w/ a raw egg drop. Here is the situation.. my daughter can only use straws and masking tape as her materials. The raw egg will be dropped from bleachers. we have looked for designs and she has made some of her own which is not working.. do you have an idea for a design where the egg will not break... she is very frustrated at this point and we have no idea where else to look. for a design. thanks brenda streeter
Project Due Date: tomorrow
Project Status: I am just starting

Re: egg drop

Postby peteryoung » Mon Dec 08, 2008 8:07 pm

Hi Nicole

As you've probably found out by now, asking for help with only a day or two before project due dates isn't a good way to relieve stress :( There's only limited opportunity to try different approaches, ask questions, etc.
I'll do what I can based on what you tell us but at this point, there's no guarantees that I understand the problem correctly.

- If the problem is to drop a raw egg from bleachers, then some means has be figured out so that the landing impact doesn't break the egg. If you're limited to masking tape and plastic straw, then you have to be ingenious. I assume "Plastic straw" is the fluffy plastic stuff that's used, for example, in Easter egg baskets to hold candy. I could be wrong, however.
- A good starting point, if it's allowed that is, is to first wrap the egg with masking tape. This has the effect of spreading out impact loads and also restraining the egg shell so that it's less likely to fracture.
- Having wrapped the egg with tape, it seems that a reasonable course of action, which perhaps you've tried, is to surround the egg in a sphere of the plastic straw. In effect, you're "cocooning" the fragile egg with a shock absorbing outer layer. Some of the NASA Mars Landers achieve the same effect by using inflatable air bags to absorb the landing loads - perhaps you've seen NASA videos depicting this effect.
- A key question, and one that's worth some testing and evaluation if you have the time, is to figure out how much plastic straw is needed to protect the egg. If allowed, I'd use as much plastic straw as possible, held together with masking tape. I'd figure that at least a 6-10 inches diameter plastic "ball" would do but that's just a guess on my part. I don't know, for example, the drop distance from the bleachers.
- Another advantage of a bigger plastic straw "cocoon ball" is that it would fall slower due to increased drag.
And the larger size ball offers more protection than a smaller ball. If you were able to create a ball that's 12" in diameter, with the egg snugly contained in the center so that it couldn't fall out, I think that would be a pretty good approach but that's a lot of straw! In this case and based on my understanding of the problem (which may not be 100% right), "size matters" where bigger is better.
- A challenging question that you may want to think over and discuss with your daughter: as the egg size is pretty well known, and so is its weight, then a good problem to think over is how to determine the minimum amount of plastic straw and tape required to have the egg survive from its bleacher drop. This type of problem solving can be labelled as "optimization" where you have to figure out the minimum resources solution to a pre-defined problem.

I hope this helps and good luck!

Peter Young
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The Aerospace Corporation
El Segundo CA
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Re: egg drop

Postby bstreeter » Mon Dec 08, 2008 9:17 pm

thank you for your reply.... I have been practicing this for a couple of days. I meant to say plastic drinking straqws... the teacher is going to supply the egg so I can't wrap it in tape although that would be a good idea.. what I have been doing is making a tube out of straws like a cylinder, placing the egg inside and making an umbrella type top out of plastic drinking straws. I tried several prototypes ... the egg broke on several attempts.... I just thought there might be a "pattern" for this type of experiment. Thank you again for your response.... Nicole and Brenda
bstreeter
 
Posts: 2
Joined: Mon Dec 08, 2008 4:34 pm
Occupation: student's mom
Project Question: we are trying to do an experiment dealing w/ a raw egg drop. Here is the situation.. my daughter can only use straws and masking tape as her materials. The raw egg will be dropped from bleachers. we have looked for designs and she has made some of her own which is not working.. do you have an idea for a design where the egg will not break... she is very frustrated at this point and we have no idea where else to look. for a design. thanks brenda streeter
Project Due Date: tomorrow
Project Status: I am just starting

Re: egg drop

Postby peteryoung » Mon Dec 08, 2008 10:13 pm

Aha, I see how that you're limited to plastic drinking straws. Perhaps you could do this - get six to eight straws and flatten them at one end. Then tape them to the egg, drooping them down more or less like a hula skirt. Do this so the straws fan out in one direction. Then repeat the process, pointing the second "hula skirt" in the other direction. To keep the straws oriented and to provide some bounciness, attach a 'belt' of masking tape about halfway out on the straws. Repeat for the other skirt. This might help provide the egg with some "spider leg-like" protection. Good luck! :D

Peter Young
Peter Young
Senior Project Leader
The Aerospace Corporation
El Segundo CA
peteryoung
Former Expert
 
Posts: 27
Joined: Thu Nov 01, 2007 8:49 am

Re: egg drop

Postby Craig_Bridge » Tue Dec 09, 2008 10:02 am

Take a look at something like dodecahedron structures. If you construct one with straws that also includes corner to opposite 5 cornerscorners, there will be an interior dodecahedron that can be used to hold the egg.
-Craig
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