6 Meter Egg Drop. HELP!

[YT2095]

a gel is better than plain water, but it does work

[insane_alien]

i was kind of assuming that materials were hard to come by and limited. water is just a handy incompressible fluid. but yeah, if you can get your hands on some gel or other viscous fluid then is good.

 

As a side note, would cornstarch/water work, since its a non newtonian fluid? i'm not sure if it would but its an idea.

[YT2095]

ya can`t use it, it`s a food product

polyacrylamide would work tho

[insane_alien]

ah yeah. bloody rules.

 

ok, new idea, decapitate a fellow contender perform a trepanation(is that even a word?) and bury the egg in generous amounts of brain(if theres any there).

[AndrewL]

hey amelia, i've done this in a camp before. Using only newspapers and a box, i succesfully managed to pass it.

 

heres wat i did:

the whole box contains purely newspaper and nothing else, but it is devided into 3 layers where the shape and folding structure of the newspaper is different.

 

the first layer which is at the bottom contains a mixture of small little chunks of newspaper rolled into spheres and lightly crumpled big pieces of newspaper. this gives enough air-space

 

the the second layer is shreded newspaper folded into a shape that looks like crinkle cut french fries. works as a cushion.

 

the third layer is just 1 or 2 sheet of plain square newspaper that completely covers the second layer. to increase area of impact

 

i hope u might find my info useful.

ps: ithink that the height doesnt matter cause it'll reach terminal velocity at about 4m. correct me if im wrong

[Ndi]

How large is you egg? I know it sounds silly, but I just measured one in the kitchen (chicken egg) and it's 6.5 cm in size.

 

Not counting drag, you have 3.5 cm (not counting top -over the egg- layers) to stop an egg that has dropped 600 cm at g. You need to expose the egg at 171G to stop it, not counting the fact that it doesn't touch the ground, the collapsible layer still takes up space, pushing it over 200G. Built pressure is sure to break the shell from inside.

 

Must be something I'm missing, but what? An attempt at terminal velocity shows that it's unlikely it will come close in 6 meters, considering a 10x10 package in free fall, in air. There's simply not enough drag, not to mention your cube is most likely rotating (thus becoming aerodynamic).

 

Again it's silly, but maybe you have a smaller egg?

[insane_alien]

thats why i suggested a liquid filled box, it supports more of the shell allowing these crazy accelerations. it also works on humans a bit, though the brain can still get mashed on the inside of the skull.

[Ndi]

Water would work, equalizing the pressure, just as solid encasing would too (same effect, more math with water). I just don't understand how papers would. Surely the weight distribution is not that even?

 

Maybe a tightly packed cardboard?

 

--

 

Now that I think about it, solid encasing is better, since the egg still has a little air bubble inside it for the infant to breathe before hatching (so I've understood) so the pressure from outside would crack it (this is in theory - doubt it will at 6 m fall).

[Cap'n Refsmmat]

The egg doesn't have to be vertical so it takes up so much space.

[CPL.Luke]

wait the dimensions were just 10X10cm that sounds like the dimensions of the base, not the height.

 

if you can have an unlimited height, I'd say put in a strong metal rod in the center of a metal base (you could probably find such a construction somewhere.

 

then put a set of strong rubberbands from the top of your rod to the egg. make sure the rubber bands are strong, and have a fair amount of stretch in them, (you may want to calculate the g forces and elasticity before hand) and then drop it, in theory the heavy metal base should ensure that it lands in the proper manor, and then the rubber bands should slow it to a halt within a distance of say 30 cm, thereby cutting down the average acceleration to 20 g's (although the maximum acceleration will be significantly higher).

 

 

also your teacher may make an exception for the corn starch, as making a non-newtonian fluid is pretty damn cool. (and also the best option)

 

as for the other fluid ideas, I don't think water would provide enough cushioning to avoid a shock when the egg finally hits the side of you container. keep in mind that some force has to act on the bottom of the egg in order to slow it down, so the only thing that the water does is increase the drag on the egg. (it won't distribute the impact)

[AndrewL]

alright..heres my opinion. (dont flame me if im wrong). if you use water, the effect is almost totally same as using concrete due to surface tension(saw in discovery channel). unless of course you can try putting a layer of mayb cotton or soft carboard over the water.

 

then again, like NDI said, droping an egg vertically down causes rotation, so this might reduce the effect of surface tension on the egg.

[Callipygous]

Now that I think about it, solid encasing is better, since the egg still has a little air bubble inside it for the infant to breathe before hatching (so I've understood) so the pressure from outside would crack it (this is in theory - doubt it will at 6 m fall).

 

the benefit of packing it in water is even distribution of pressure across the whole egg. its virtually impossible to break an egg with even pressure.

[[Tycho?]]

alright..heres my opinion. (dont flame me if im wrong). if you use water, the effect is almost totally same as using concrete due to surface tension(saw in discovery channel). unless of course you can try putting a layer of mayb cotton or soft carboard over the water.

 

then again, like NDI said, droping an egg vertically down causes rotation, so this might reduce the effect of surface tension on the egg.

 

They're not talking about dropping it into water, they're talking about putting the egg in a box with water in it. Surface tension does not factor in.

 

I remember doing something like this back in middle school, although we only had to drop our eggs from 2 meters or something. Which was kinda pointless, since just encasing the thing with foam worked perfectly well. I tried to be creative, and made a sort of scaffolding and suspended the egg inside using elastic bands. 10 cm isn't that much space to work with for a 6m drop though, so the liquid ideas are probably better.

[Ndi]

wait the dimensions were just 10X10cm that sounds like the dimensions of the base, not the height.

 

if you can have an unlimited height, I'd say put in a strong metal rod in the center of a metal base (you could probably find such a construction somewhere.

 

I assumed it's 10x10x10. If no height, you use a string and make a yoyo.

 

The egg doesn't have to be vertical so it takes up so much space.

 

I just thought that if no liquid is used, only half of the egg is taking the pressure and the egg is *much* more resilient on the pointy end. Position is irrelevant in water, obviously.

 

the benefit of packing it in water is even distribution of pressure across the whole egg. its virtually impossible to break an egg with even pressure.

 

My phrasing was lacking. It should be: Due to the air bubble in the egg (which is compressible), it is marginally better in theory to use an egg encased in solid rather than a case with a liquid. I doubt it will make a difference in practice, this is only theoretical and only marginal.

[CPL.Luke]

your not going to get an even pressure distribution if you use water. what will happen is the box will fall, hit the ground, and cause the water to come to a halt very rapidly,(also sending some shockwave up through the egg. Then the egg will continue to fall and hit the bottom of the crate.

 

I would highly doubt that that shockwave would significantly slow the egg.

[insane_alien]

CPL, the egg is held in the middle of the box by foam struts otherwise it would sit on the bottom and likely crack, the foam keeps it from touching the sides and the water allows it to be slowed don really really fast without breaking.

[J.C.MacSwell]

CPL, the egg is held in the middle of the box by foam struts otherwise it would sit on the bottom and likely crack, the foam keeps it from touching the sides and the water allows it to be slowed don really really fast without breaking.

 

I like this idea IA. As long as the foam is fully saturated you are only dealing with the shock wave. And if it is not quite fully saturated much of that would be reduced without excessive pressure differential (other than the shock wave). A good time to fine tune this would be around breakfast time with a large family. It might break the yolks but not the shells.

[CPL.Luke]

if the foam is solid (which they would have to be if they were going to keep the egg from falling to the bottom), then you would still have a decelleration problem. the water does nothing.

[insane_alien]

no, its soft foam, it doesn't have to support the whole egg, just what buoyancy doesn't take care of.

[Ndi]

You can modify the composition of the water for buoyancy.

[insane_alien]

yeah, but if you get the egg neutrally buoyant its still going to drift about, the foam just provides a little force to keep it roughly centred

[Rocket Man]

when i suggested water, i was thinking more along the lines of actually reducing the inertia of the egg by countering it with bouyancy.

when it's immersed in water, it only weighs a few grams. you'll need to exert far less force on the egg itself to slow it.

 

a porous sponge wrapped around the egg and possibly lining the box will provide pleny of force to slow the apparant mass.

i havent actually tried salt, but you could probably get the egg to be neutrally bouyant. an egg is mostly incompressible, i'm concerned about the gas in the bottom though. the shell will probably provide enough counter force. i would try to find the critical presure, but the equipment i have is too small and i can only muster 3 bar

 

if the shockwave breaks the shell on the tests, add vinegar to the mix the night before.

 

if you use water, you can still have a dampenning system attached to the bottom. you don't need all that much water.

 

 

how would you calculate the max pressure spike assuming 200G and a fluid as dense as water?

[Callipygous]

isnt it the mass of an object that effects it inertia, not its weight?

 

as for the rule on no food products, are you allowed to use salt or vinegar?

[CPL.Luke]

callipygous is right the mass matters, not the weight.

 

alright assuming that the foam strutsdo nothing but keep the egg in place until the box hits the ground, then you still have the problem of the water not providing sufficient drag to stop the egg, and it will continue to fall and subsequently crack on the bottom of the box.

[Ndi]

Back to filling the box with foam/hard substance?

 

I'd go for complete force spread over the surface over the braking of the egg. That is, I'd feel safer with an egg that's perfectly fit in a metal mold (theoretically speaking) versus a suspension/breaking system with a simple brace.

 

You can't really break an egg if it's contained. Whatever forces the contents apply via inertia will have to squeeze wall molecules apart before breaking the walls, which is probably *way* over terminal velocity.

 

So I'd say get a 10x10x10 box, fill it half way with something hard, non-adherent (oil the egg if needed be) and put the egg half-in. Once it hardens, you have half-of-cast for the egg. Then you can either make the other half the same way or use a sheet of paper over the assembly and make the other half over it (paper will rip when opening the halves and allow retrieval of egg).

 

Now all you have to do is make sure the cast is actually touching the egg over most of the surface. Use something with high viscosity if the mold shrinks, like honey (i know it's a food), solid hand lotion, motor grease, etc to keep the egg walls in contact with the mold. That should hold at the box's terminal velocity?

 

Now all you do is make sure it doesn't come apart in flight or at landing. Rope? Plenty of duct tape?

 

P.S. The egg will be OK on the outside but you might have an omelet inside at high velocities.