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12 Foot Egg Drop Problems: Grandkids Have Chosen Their Design, How Would You Do It?

12 Foot Egg Drop Problems: Grandkids Have Chosen Their Design, How Would You Do It?

12 Foot Egg Drop Problems: Grandkids Have Chosen Their Design, How Would You Do It?

(OP)
The twins (7 years old) have chosen their design for the school's egg-drop problem: Drop an egg 12 feet. Don't break the egg. Use anything you want. Max "envelope" size is 7x7x7. Egg must be inside a sealed sandwich-style plastic bag when dropped (This prevents eggs leakage.) Other than that?

Pretty much anything goes.

So nbr 2 twin wants to use "BIG bubble wrap. Lots of tape. Red tape. Big, thick red tape. Really, really wide super-strong red tape." OK - We'll see how that goes. (Not sure what the "red" part of the "Big Red Tape" is going to do, but "Hey! He's the customer." Fastenal does have 2 inch wide red duct tape.)
Nbr 1 twin wants to use "Fluffy cotton, AND Big bubble wrap, and yellow tape." (Big bubble wrap must be a 7-year old male thing, I guess. Can't use the wimpy little bubble warp. Obviously, yellow tape is going to be better than red tape. No spec's on the width of the yellow tape though? )

But.

How would you do it? I'm wondering if dipping the original "raw egg" in a polymer or epoxy would help strengthen the egg itself - but without adding mass or much thickness. Then wrapping in the bubble wrap, then a frangible nested pair of outside boxes - each cardboard box only loosely taped together to allow the cardboard to flex.

RE: 12 Foot Egg Drop Problems: Grandkids Have Chosen Their Design, How Would You Do It?

Land it in a tank of water with a foam pad on the bottom? The egg is stronger in one direction than the other, so attach flights to ensure it enters the water 'strong end first'. Ditch the envelope.

RE: 12 Foot Egg Drop Problems: Grandkids Have Chosen Their Design, How Would You Do It?

Is that even allowed? The extreme would suspend the egg in a container of glycerin or somesuch.

What about a parachute or something that will increase aerodynamic drag? Reducing the delta-V is certainly an approach to reduce the impact shock, particularly since total kinetic energy is proportional to V^2

TTFN
I can do absolutely anything. I'm an expert!
FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers

RE: 12 Foot Egg Drop Problems: Grandkids Have Chosen Their Design, How Would You Do It?

You didn't mention what color the tape on your method was going to be...


I'd use a finned paper towel tube so it would hit long-end. Then deaccel the egg for the tube length using something that gives but breaks in the process. Perhaps 200 cross-tube toothpicks.

Keith Cress
kcress - http://www.flaminsystems.com

RE: 12 Foot Egg Drop Problems: Grandkids Have Chosen Their Design, How Would You Do It?

I did this when I was a kid. For us it was a 7-storey drop. Onto a target. The target eliminated the parachute options, or at least rendered them less usable. I weighted mine to ensure that it would land on the target. Probably came as close as possible to terminal velocity (as you can from 70+ft). Everyone thought the egg would be flat on the inside of my container. I used bubble wrap - and it worked amazingly well. The egg was completely intact - mine was only 3/12 that survived that day.

I still have that Easter basket I dropped the egg in - gave it to my daughter to use to collect Easter eggs.

Air is a great cushion.

RE: 12 Foot Egg Drop Problems: Grandkids Have Chosen Their Design, How Would You Do It?

(OP)
1. Start with a perfect sphere ...
2. Get a looooooooooooooong roll of red duct tape...

RE: 12 Foot Egg Drop Problems: Grandkids Have Chosen Their Design, How Would You Do It?

Just throwing out an idea... Put the egg inside an "egg"...
Get a large plastic jug - one with a mouth big enough for the egg to pass through.
Fill jug with jello, lower the egg into the jello & suspend in the middle of the jug.
Tying the string around the egg might be tricky... maybe tie a basket...
After the jello cures, top off the jug with water and close the cap with no air.
Tape around the jug several times (equatorial and polar wraps, overlapping) with the red tape (not the yellow tape, everyone knows the yellow tape doesn't stand a chance).
Now cover that in bubble wrap the way the kids want to, and heave ho!
Jello may not be the ideal medium, but it's a kid-friendly one.

STF

RE: 12 Foot Egg Drop Problems: Grandkids Have Chosen Their Design, How Would You Do It?

My daughter did this last year from a 100' drop - fire department "loaned" a ladder truck.

The number of eggs to be dropped was assigned on the day of the drop - it could have been one to three. Of course she had three.

She used a shoe box that had three cardboard inserted dividers with a hole in each divider. She wrapped the eggs in an old pair of her mom's pantyhose and placed them in the box so there was a small amount of give in the pantyhose (so the egg was not rigidly supported). The eggs were oriented so the bottom/top of the egg was oriented along the long dimension of the box. Around that, she put puff corn (think cheese puffs, but shaped like popcorn) for cushioning. The lid was taped shut.

In the bottom compartment, she placed a small bag of sand. This was used to make sure the box did not flip or rotate.

None of her eggs broke.

RE: 12 Foot Egg Drop Problems: Grandkids Have Chosen Their Design, How Would You Do It?

f=ma. The acceleration of interest is how long does it take to slow to a stop. The longer the time to stop the lower the acceleration and therefore the force. I'd get a heavy duty 1 qt ziplock, fill it with jello, partially set it, put the egg in, put the first ziplock inside a gallon ziplock and fill that with jello. I wouldn't worry about direction of impact at all.

David Simpson, PE
MuleShoe Engineering

In questions of science, the authority of a thousand is not worth the humble reasoning of a single individual. Galileo Galilei, Italian Physicist

RE: 12 Foot Egg Drop Problems: Grandkids Have Chosen Their Design, How Would You Do It?

Just make sure the adult performing the drop has never worked for FedEx or UPS.

It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.

RE: 12 Foot Egg Drop Problems: Grandkids Have Chosen Their Design, How Would You Do It?

Many many years ago, when Styrofoam was the newest packaging material, A salesman from Square D was showing me the latest design magnetic motor starter. As well as a new design starter, they had gone with new packaging. Moulded Styrofoam. He told me that to test the new packaging they had mailed ah starter to a branch office across the country with instructions to re-address it and mail it back.
When it arrived back undamaged they knew that they had a good packaging method.

Bill
--------------------
"Why not the best?"
Jimmy Carter

RE: 12 Foot Egg Drop Problems: Grandkids Have Chosen Their Design, How Would You Do It?

I'd read the rules closely and (almost) cheat.

Wrap egg in 1-2 thin layers of small (sorry, no fun I know) bubble wrap, then saran wrap. Fill sandwich bag with jello and freeze it solid with wrapped egg inside. Rules should prohibit hard boiling the egg, but who would think to specify that you can't freeze it? The jello will thaw a bit on the outside by the time it's dropped, and absorb some shock, but the egg will still be frozen solid inside and still have a solid core of jello around it.

The egg will float in the bag, but if you drop it egg side up, it should stay that way and land jello side down.

RE: 12 Foot Egg Drop Problems: Grandkids Have Chosen Their Design, How Would You Do It?

Has anyone considered using a non Newtonian fluid (e.g., cornstarch and water mixture)?

RE: 12 Foot Egg Drop Problems: Grandkids Have Chosen Their Design, How Would You Do It?

Seems like a Newtonian fluid would provide too hard of a surface once impact began... but I'd like to think about it a bit more.

Dan - Owner
http://www.Hi-TecDesigns.com

RE: 12 Foot Egg Drop Problems: Grandkids Have Chosen Their Design, How Would You Do It?

Peanut butter appears to be the "fluid" of choice rather than Jello for egg cushioning. For some who may not be aware; the concept of fluid cushioning is that the egg floats in the fluid, so it has essentially no weight. This is true at any g-force. But the outside container must be strong enough to not burst from the fluid pressure generated by inpact, so I don't think a zip-lok bag would be suitable for the outside container. Placing the egg into a full peanut butter jar seems to work. The draw back to this technique is that it is heavy and some rules reward light weight. Also air spaces in the egg will feel the g-forces, so you want to use a really fresh egg.

RE: 12 Foot Egg Drop Problems: Grandkids Have Chosen Their Design, How Would You Do It?

My daughter's competition specifically forbade use of peanut butter.

RE: 12 Foot Egg Drop Problems: Grandkids Have Chosen Their Design, How Would You Do It?

These days that would qualify as a 'terror hate attack' on a sizable subgroup of students.

Keith Cress
kcress - http://www.flaminsystems.com

RE: 12 Foot Egg Drop Problems: Grandkids Have Chosen Their Design, How Would You Do It?

Almond butter :)

RE: 12 Foot Egg Drop Problems: Grandkids Have Chosen Their Design, How Would You Do It?

ZDAS lined out the problem mathematically for you. I'd use just about the softest material I could find and lots of it so that the 'a' in ma is as small as possible. Rearranging constant velocity equations means it needs to travel a long way to decelerate slowly hence the 'lots of it'.

Posting guidelines FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm? (probably not aimed specifically at you)
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?

RE: 12 Foot Egg Drop Problems: Grandkids Have Chosen Their Design, How Would You Do It?

My daughter used the nylons, you put the egg in and twist it just enough to support them and hold position.
She worked out how to support it with four separate pieces, running diagonal across a the inside of a 6" box, then she used very soft packing peanuts to cushion it inside a 7" box.
It took a few tries to get the tension correct, but it worked well.
I like the idea of fewer supports and weighting one end of the box.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube

RE: 12 Foot Egg Drop Problems: Grandkids Have Chosen Their Design, How Would You Do It?

(OP)
Status Update, After-Action Report

1. Both twins decided to use the red tape.
2. After nbr 2 saw how nbr 1 twin decorated an external box, both decided to put the red-tape-wrapped-large-bubble-wrapped egg inside 7x7x1 foam squares stuffed inside a 6x6x6 cardboard box. Then wrapped the cardboard box in, of course, the approved-and-specified official red tape.
3. Both eggs survived.
4. Both twins happy.
5. Grandmother happy.

RE: 12 Foot Egg Drop Problems: Grandkids Have Chosen Their Design, How Would You Do It?

Definitely the red tape.
Good result for the twins, next might be a soft landing on one of our planets.

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)

RE: 12 Foot Egg Drop Problems: Grandkids Have Chosen Their Design, How Would You Do It?

Hooray!

STF

RE: 12 Foot Egg Drop Problems: Grandkids Have Chosen Their Design, How Would You Do It?

At a family camp I go to each summer, we have the egg drop competition from a 20-foot-high balcony. One year, I decided to enter with a piece of "performance art". I just taped the egg to the underside of a log and dropped it. I called it "Die-a-log". Some people appreciated it; others didn't...

RE: 12 Foot Egg Drop Problems: Grandkids Have Chosen Their Design, How Would You Do It?

I looOOVe it!

Keith Cress
kcress - http://www.flaminsystems.com

RE: 12 Foot Egg Drop Problems: Grandkids Have Chosen Their Design, How Would You Do It?

wilson, did you cut it open afterwards? You should always keep an open die-a-log...

Dan - Owner
http://www.Hi-TecDesigns.com

RE: 12 Foot Egg Drop Problems: Grandkids Have Chosen Their Design, How Would You Do It?

please don't follow this up next year with Cat-a-log!

RE: 12 Foot Egg Drop Problems: Grandkids Have Chosen Their Design, How Would You Do It?

A bucket full of fiberglass insulation. I tried to break the egg by throwing the bucket off the house onto garage concrete slab and couldn't.

A parachute would be kind of the clever solution instead of trying to make something take a hard landing.

RE: 12 Foot Egg Drop Problems: Grandkids Have Chosen Their Design, How Would You Do It?

Thinking outside the box, or maybe inside the coop;
Can the egg still be in the chicken.
My wife just bought her first 14 laying hens. That may have had something to do with my question.

Bill
--------------------
"Why not the best?"
Jimmy Carter

RE: 12 Foot Egg Drop Problems: Grandkids Have Chosen Their Design, How Would You Do It?

(OP)

Quote (waross)

Thinking outside the box, or maybe inside the coop;
Can the egg still be in the chicken.

That may well work (Which brings to mind the infamous, "I swear I thought turkeys could fly" Thanksgiving TV episode" quote ...) but the chicken is likely to opposed being thoroughly wrapped in the required red tape.

RE: 12 Foot Egg Drop Problems: Grandkids Have Chosen Their Design, How Would You Do It?

I loved that episode. grin

Bill
--------------------
"Why not the best?"
Jimmy Carter

RE: 12 Foot Egg Drop Problems: Grandkids Have Chosen Their Design, How Would You Do It?

The chicken probably wouldn't fit within the max dimensions, and if it did, it wouldn't be very happy about it.

RE: 12 Foot Egg Drop Problems: Grandkids Have Chosen Their Design, How Would You Do It?

(OP)
"The chicken probably wouldn't fit within the max dimensions"

Welllll, that degree of displeasure of the chicken might well depend on the speed of insertion of the egg, the relative egg-and-chicken diameters, the number of times the egg had been inside any particular chicken, and the LBGT values of the egg in question (er, in chicken).

RE: 12 Foot Egg Drop Problems: Grandkids Have Chosen Their Design, How Would You Do It?

hi racookpe1978

A number of years ago I did this egg dropping contest from 20 foot and my egg survived.
I wrapped drinking straws around the egg horizontally and longitudinally attached with tape and left straws hanging out at each end so it looked like a Christmas cracker, the idea behind the hanging out straws was to act as a energy absorber no matter which way the egg landed, anyway my egg didn't break.

“Do not worry about your problems with mathematics, I assure you mine are far greater.” Albert Einstein

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