I have to do an "egg drop" for a physics project and I was wondering if you guys could help me out. The rules are that I must make a device using only paper products (cardboard, paper, kleenex, toilet paper, etc.) and scotch tape (the thin clear tape) to keep an egg from cracking when dropped from the bleachers of our football stadium. This is about 2 or 3 stories. I'd like to know if any of you have any ideas and if any of you have ever done something like this, what sort of design won?

Oh, by the way, points are awarded as follows:

Egg breaks - 0 points
Egg has small cracks (but doesn't "bleed") - 15 points
Egg survives- 25 points

Mass:
100 grams to 20 grams - 5 points to 30 points (at 10 gram intervals)

Fall time:
> 0.5 s - 10 points
> 1.0 s - 8 points
> 1.5 s - 6 points
> 2.0 s - 2 points
< 2.0 s - 0 points

The above facts aren't too important, but the idea is to get the egg to go from a height of two stories to the ground (concrete) as quickly as possible without breaking the egg. I'll post the design I came up with soon.

a suggestion: talk to the people that did this last year, or term, or whatever.  they can tell you the secret.  

other than that, i have no idea.

There are four main designs I've seen in my research that work in an egg drop contest:

1) The parachute/propellor. There is some sort of parachute or propellor attached to the top of the egg to slow it down as it falls. The egg is almost always in some sort of basket to cushion its landing.

2) The soft-box design. The egg is contained in a box full of "soft cushiony stuff" such as cotton, kleenex, or packing peanuts. The box falls straight to the ground, but the egg is cushioned inside.

3) The pyramid. The egg is in some sort of pyramid (almost always matchsticks or toothpicks that are glued together) that will cushion its landing.

4) The cone. The egg is in some sort of paper or cardboard cone. The cone will crumple/break on impact much like the front of a car in an accident to cushion the egg. This is the design I think I like the best.

There may be other designs that work, but I haven't seen any yet. I can find a picture for you if you'd like to see any of these designs.

wrote on Apr 23^rd, 2006 at 12:08am:

a suggestion: talk to the people that did this last year, or term, or whatever.  they can tell you the secret.   other than that, i have no idea.

This is my teacher's first year teaching at this school. None of the other Physics teachers have made their students do projects like these (there are 4, this is the last one) before. So, I figured the Physics geniuses on this site might be able to help out.


Anyway, my design is as follows:

I chose the cone design (like I said, it's my favorite). Below are pictures of the device:

http://www.altay.vilko.net/dl//sling/egg1.jpg

Here is the side view of the device. The egg and quarters are for size reference. It's basically a sheet of paper rolled into a cone with a piece of kleenex inside for cushioning.



http://www.altay.vilko.net/dl//sling/egg2.jpg

Here is a top view of the device. You can see the kleenex in this view.



http://www.altay.vilko.net/dl//sling/egg3.jpg

And here is the device with the egg in it. The egg fits snugly into the top of the device.

what a shame.

i think that the cone would work best.

in this determination, i assume that you do mean cone, and not cylinder.  a cylinder will probably not crumple, but reamin sound when it hits.  a cone with crumple if it hits point first.  you should pick something that will sort of "slap" the ground, so that energy can be transfered to the ground very quickly, taking shock away from the agg.  

wrote on Apr 23^rd, 2006 at 12:19am:

you should pick something that will sort of "slap" the ground, so that energy can be transfered to the ground very quickly, taking shock away from the agg.

I'm sorry, but this is wrong. You DO NOT want to transfer the energy to the ground quickly. If the egg hits the ground directly, the energy will transfer as quickly as possible. You want to slow down the time of impact.

Impact = Force*time

So if you lengthen the time of impact, you'll lessen the force. That's what cushions are for, they lengthen the time of impact, so that the force is reduced.

EDIT: That should be "Impulse = Force*time" not "Impact = Force*time", but it's the same idea anyway.

Think like a porcupine :) Or like a bee (a colony rather)

Only paper products and scotch tape. Too bad there are no straws or glue allowed :(.

Wrap egg up in kleenex. Wrinkled not rolled, this shall give it a more collapsable 'honeycomb' effect. Wrap this in the tape so as that it won't come off of the egg. Wrap another wrinkly layer over that but use the tape sparingly, so as that it fits lossely.
Take sheets or paper and roll them along the diagonal to form a very narrow (thinner than a pencil) cone which is long (longer than a pencil by a good amount). It should resemble a spike. I suppose you could also use very thin card board strips (without rolling into a cone).
Then, tape the cones which we shall now refer to as spikes, to the kleenex wrapped egg. Don't tape too tight, but in a manner that will prevent it from moving more than a couple inches without tearing tissue. This will form a very spikey ball with very little air resistance.

Drop this... It should fall very fast since spikes of paper don't take up much room, and the kleenex wrapping has a negligible effect. Upon impact the spikes will bend and crumple, they will also sheer off of the kleenex, kleenex will 'unwrinkle' and perhaps tear, absorbing energy. All goes well and the egg will end up unscathed in a tangled mess of paper, tape, and kleenex.

To really impress your teacher... make it turn the energy of impact into electricity :)

Oh, sorry I forgot to mention something :-[. We will be given the egg the day of the testing and then we'll be given an extra 10 cm of tape to seal the device or tape it to the egg or whatever. So I'm afraid I wouldn't be able to do your idea, though it sounds like it would work well.

boil an egg ahead of time and switch it out when you guys are getting ready.  that way it won't "bleed", even though it may crack,  you will still get 15 points in that area of the contest.  

btw, i as just kidding.  i don't really suggest trying to do that, as the teacher will probably have some sort of way of identifying the eggs.

Too bad, I came up with many great improvements to that idea too!

on a more legal note you could premix some glue made from paper products and smear the egg in it for an epoxy like coating. Not probable but it is possible...

like paper mache or something?

How much of the ingredients are you allowed? If it is a high amount, cant you cut the paper into strips, and use them like packing peanuts? The Porcupine paper Idea can work too, without the use of tape and glue. Make the holes very small, so that the rolls are held together by the force.  After that, it's just a matter of how you lay out the spikes.
   Think of the way the spikes on a medieval mace are. No matter what, you will be hit by them. Same thing with the spikes. No matter what, the spikes will hit, absorbing some of the blow.  if its allowed, I suppose that you could wrap the paper around a thin strip of cardboard, for extra support.

I can't use paper mache because I'd need to use glue. The only adhesive I'm allowed to use is the stuff on the back of a piece of tape... By the way, I am not allowed to touch the egg until the day of testing, and even then, I'm only given 10 cm of tape to keep the egg in my device. So I can't do stuff like coat the egg with something or attack tons of spikes to the egg because I wouldn't be able to do that with 10 cm of tape (and about 5 minutes).


wrote on Apr 23^rd, 2006 at 1:22am:

Oh, sorry I forgot to mention something :-[. We will be given the egg the day of the testing and then we'll be given an extra 10 cm of tape to seal the device or tape it to the egg or whatever. So I'm afraid I wouldn't be able to do your idea, though it sounds like it would work well.

Maybe you can prepare a porcupine shell, with an opening to add the egg later.
If you make small holes in strong paper, and roll or fold paper to a small diameter, you can push them through the heavy paper and it will stick in place then.
Or look into paper folding, you can do amazing stuff with just folding.

Willeke

if the porcupine concept evolves into a workable form, use many different length spikes and cut many little notches on them as points to break (you'd be surprised at how strong a tightly rolled piece of paper is)

On another note in your current cone form, the side that is supposed to be the bottom is kept as the bottom because of weight distribution and air resistance. Instead of air resistance in the direction, why not use fins, such as on a WWII bomb to keep it right side down. This would make it faster and score more points.

Maybe putting a scaffolding of spikes onto the bottom of the cone?

Additional thought, on the bottoms of the spikes put a band of tape a couple inches up. Cut through so that there are many little slips  of paper so that the whole thing resembles a broom. Bend them over, and tape them back so it looks like this http://www.villagekitchen.com/mfg/matfer/ktool/whisk/111025.jpg
If someone has a problem with me using that image I'll get rid of it, but I just see it as publicity for them.

I'm not sure if the amount of energy it would absorb would be any good, (probably not) but it's just a thought.

I've tried that design (the egg beater one) with paper before. It was to build a paper tower with a single sheet of paper. It couldn't hold itself up at all, so I doubt that it will be able to cushion the landing (and it's a huge pain to put it together). I like the idea of fins. How will fins help it? I don't see how they'd make it go faster, but I can see how they'd help it go straight. Anything I should know about adding fins?

Fins would make it look faster and so it would be faster... just kidding. My thought was to replace that voluminous, rear portion of the cone with fins. They'd serve the same purpose -stabilizing flight, ensuring the device lands on the braking contraptions- fins wouldn't create nearly as much drag in the downward direction, and far more in the side to side direction.

P.S. what about concentric cones with crumpled tissue paper between them?

wrote on Apr 23^rd, 2006 at 7:34pm:

what about concentric cones with crumpled tissue paper between them?

I didn't think about this possibility. I was thinking about possibly taping two sheets of paper together, then rolling them into a cone, so it would be twice as hard to crumple as the original. However, putting a kleenex between the two before I tape them together and roll them up may help to cushion it a bit. I think that if I rolled the two cones separately, then put kleenex between the two it wouldn't stay together as well.

I think several layers would be best. The one closest to the egg being the strongest, the one hitting the ground first being the weakest.

Remember, the name of the game is, "Disperse all energy to anything and anything other than the egg". And the best way to do this is to isolate the egg at as many levels as is possible from the ground.

Right now, I think the the best design would be:
A reinforced cone, made of heavy paper or cardboard lined with tissue paper to cradle egg.
LONG fins to stabilize flight.
A secondary cone (made of two sheets of paper) sliding over the first with shredded paper or kleenex as padding between the two (a crumpled ball of scotch tape placed over the tip of the first cone would be perfect. It should be fitted loosely (at no point directly touching the other cone).
A third cone, longer but not wider, of a single piece of paper, and fully fitted with  spikes should be slid over the second with very little padding between the two. At this point, the bases of all three cones should line up, and taping them togher should be no problem.
The spikes should be construced weaker than those mentioned earlier. They should have many little cuts on them as predetermined beding points - the most severe of which are at the tips. With luck, each spike would bend at several of the points.

Contraption falls. The spikes bend at many points and sometimes sheer off of the sides of the cone. They splay out. This all absorbs energy and slows the egg, which feels nothing at this point. The tertiary cone then impacts and easily deforms. As the secondary cone receives impact, it is compressed against the primary cone (with the kleenex absorbing the energy) and slightly deforms. The egg continues to fall... much slower however. Padding and the primary cond absorb any remaining energy.

Of course this is all assuming that device remains perfectly upright the entire journey... not going to happen. For this reason, more (weak) spikes should be attatched to the sides of the cone, possibly even at angles greater than horizontal. During lopsiding (not a forceful event) spikes and fins will absorb energy.

I suppose I should elaborate on the primary cone for clarification. Lined with fairly compressed tissue paper, then loosely cumpled tissue paper placed towards tip of cone. Egg is placed on that layer and another loosely crumpled layer of tissue on top of that. 10 cm of tape keeps the whole thing nice and safe, and is easily done in under five minutes.

I was thinking of fins something like this.. just longer http://im.edirectory.co.uk/products/1306/i/vortexhowler.jpg" name="post_img_resize_5" alt="" border="0" id="imagecount5" style="display:none" />http://images.google.com/images?q=tbn:kA-YXmmBGgp42M:http://im.edirectory.co.uk/products/1306/i/vortexhowler.jpg

O and for a sense of scale I was thinking around eight inches from the back of the first cone to the tip of the third (so excluding spikes and fins). But this could be widely varied. The only concern would be if the egg became placed too far back in the device making stabilized flight and impact more difficult.
I suppose this is more than you ever wanted when posting :P. I know that I sound 'bossy' but it's just the easiest way to write. (interjecting with, "but i understand that you could do it differently or may not like the blah blah bl-..." would be even more annoying.

Good luck, consider implementing an idea or two of mine :)

P.S. Altay, just noticed that in three more posts you're a senior member... I think.

WOW. That would be one giant contraption! :o I don't think it'd be a good idea to make a device that you don't know which way it will land. The advantage of the simple cone is that due to the fact that it'd very aerodynamic, it should always land point first (unless you drop it egg first). I think I'll  test the basic design first. Then if it doesn't work I'll try a double paper design. If that still doesn't work, I'll test a double paper with fins. And if that doesn't work I'll probably try some more intricate contraptions. The most vital criteria for success with the cone design is that it hits point first. If you make it too complicated, you could put it off balance to the degree that it flips over. If you have a design that could flip unpredictably, you've defeated the purpose of the basic cone (and then you're looking at more of a porcupine design). Hopefully I'll be able to test some of my designs in the next week, but I don't know for sure.

Haha, indeed. This is why I stressed that the spikes should be made very weak. All in all, I don't think the spikes would have any impact on the flight, especially with fins attatched, since they'd be very narrow and equally distributed. The way I'm thinking of the design is not to look at it as 'one cone with a bunch of stuff piled around it' but as one cone (the tertiary) with a lot INSIDE of it, and some on the outside. Anyway, spikes, if not for initial impact may be helpful once the cone lopsides. There should be a bonus round from four stories ;D


If a single cone with a bit of padding works, all the better though :)

In the few egg drops i have seen the cone always seems to win. when i was forced into one i made a parachute, it worked pretty well but i was still beaten by all the cones. Its odd the ones i saw had the egg at the tip of the spike, with the wide bottom falling down. They alos had these fancy fins and stuff that kept it falling right.

So, pretty much like a model rocket flipped upside down?

http://www.hobbyplace.com/rocket/est1292b.gif

Something like that flipped over with the egg between the fins?

Well we had to do this in my high school a couple years back. I actually had the winning design.
Here's what i did

I took computer paper, and cut them into 1/2-3/4" strips lengthwise. I then made a wider opened cone (Force = Pressure / Area  so greater initial hitting area the less the force) and with the paper, I made them standing up and coiled them loosely. Inside the cone I stacked and restacked the strips of paper. So it was  wider and wider.  Lastly I put a very small parachute onthe end to make sure that the side i wanted to hit first did.

i made a tissue paper cradle on the top to hold the egg in the cone.

It seems like a little hard to understand but below are some pics i just made (gimme a break with these tho  :P)

http://www.personal.psu.edu/pad178/stuff/slingpics/egg.jpeg

This is a very simple honeycomb design, and it bascially cuts the impact force down from the widen bottom, and makes the impulse longer so the actual force on the egg is quite minimal

lemme know what ya think

Interesting design. If it was the winning design it must have worked well. What exactly was the purpose of the paper coils though?

well the paper coils are depicted in the part where it ways paper thickness.   its a bad drawing/description, lemme try again

The paper coils are basically stacked on top of eachother. That is what "fills" up the flattened cone. When the egg is dropped and is crushed, each paper will compress and then the next will compress and so on and so forth. The paper coils function is to length the time of impact so the impulse on the egg is much longer.

you can even slightly bend the paper beforeyou coil it so that it kinda has some spring to it and that will even work better than "straight" coils

if that isnt good enough, i can make one really quick and dirty and take some pics

lemme know