How do I keep an egg from breaking ? PLEASE READ

[lizardth]

Time is relative. Use a live chicken...

 

[blamb425]

In elementary school, we had to do this using paper. I just rolled mine into a cone. Worked like magic.

 

[Zebo]

When i did this project, back in the 1970's, like every kid in america, I used rubber bands like 200 wrapped around egg in opposing fashion and affixed to box. Worked good.

 

[Zebo]

If you want to to tell you how to win at soap box derby I'm your man as well.

 

[dullard]

As much as I think Gayner is a troll, I'm on his side in this case. Putting cereal instead of peanut butter (or whatever) in the same sized container (no bigger than 5"x5"x5") isn't going to make a significant effect on the velocity when we're talking 30 feet. He never said mass is irrelevant either. You extrapolated that on your own.

He rolled his eyes when I mentioned weight and fought hard against me. I don't think that is extrapolating too much. But, since you too disagree with me, I figured I might as well do some actual calculations. I will make a couple of assumptions, feel free to adjust the assumptions as you see fit and redo my math.

I will assume the box is a 5" cube. I use this 5" cube since Gaynor was worried about the box flipping around and a cube will reduce the flipping around vs a different shape. Although, a 5" cube is basically what I recommended to begin with. I said to use the 5" x 5" area for falling, add in the height of the cereal (or other padding) and the height of the egg (which must be verticle due to the rules) and some air space above it and the height is right around 5".

I will assume the air is still, at atmospheric pressure, and roughly room temperature. Density is then ~1.2 kg/m^3.

I will assume that the cube is dropped with a point towards the ground. This will minimize the drag coefficient and thus minimize the box from flipping around. It will also maximize the amount of padding that can go between the egg and the ground. The area of drag is then ~50 in^2 and a drag coefficient of a cube at and angle is 0.8.

I will assume an egg of 50 g weight, that is a slightly small egg, but certainly not a tiny egg. I will assume a cardboard box of 57.6 g, since that is based on the mass of a typical 5" cubed cardboard box.

I will assume cereal of a density of 0.09 g/cm^3 (rice krispies) vs peanut butter with a density of 0.76 g/cm^3. I use peanut butter as a comparison since you specifically mentioned it. The comparison would be far worse with a denser packing since even peanut butter isn't very dense.

I also assumed a 5" cube volume with 80% packaging material for a total of 100 in^3 of packing material weight. (I didn't bother to add the weight of the air in the box).

I will assume wikipedia is correct in its drag formula for the velocity of a falling object.

Results:
Cereal + egg + box mass = 250 g.
The box with cereal lands in 1.497 s, with a velocity of 10.4 m/s, and a kinetic energy of 13.4 J.

Peanut butter + egg + box mass = 1348 g.
The box with peanut butter lands in 1.390 s, with a velocity of 12.7 m/s, and a kinetic energy of 109.0 J.

So, the box with peanut butter would have 8 times more kinetic energy to dissapate than the box with rice krispies due to its 5x heavier mass and 23% higher impact velocity. To me, 8 times the kinetic energy is a significant difference. Do you disagree?

Of course, I'm not knowledgeable enough to know if peanut butter can handle the 8x kinetic energy better than rice krispies with 1x the kinetic energy.

Edit: fixed a typo in the numbers, but my point was the same.

 

[waffleironhead]

Penut Butter

I did this. it worked great.

 

[bobdole369]

Yea, that's just the thing. She had a week to do this, but just now mentioned it tonight.

Then perhaps the student should fail. Experiencing the embarrassment of failure is likely to prevent the procrastination in the future right? Oh this is today's generation who simply don't care...... In any event by helping now the parent reinforces the notion that procrastination is OK.

There is a reason I'm not a parent.

 

[NuroMancer]

Funniest solution I've seen is to put the egg in a condom.

The elasticity of it works perfectly. I only wish I had thought of it.

 

[overst33r]

F=ma

Styrofoam with bubble wrap.

Worked for me.

Another group used floral foam.

Or you could stuff it down the throat of a cat and throw it off there...

 

[gorcorps]

If you rob your child of doing this herself she'll never become an intelligent, productive member of society. She'll end up huffing paint thinner and blowing guys for food in truck stops. Do you really want that?

 

[Yeem]

Boil it and cover it with a thin layer of candle wax.

 

[fatpat268]

Did this in elementary and middle school, both times I was limited to a select few materials.

I could only use drinking straws, masking tape, and scrap cardboard. That was it. I'd love to have been able to do it with some different materials...

 

[MotF Bane]

Time is relative. Use a live chicken...

Best answer!

 

[hanoverphist]

My daughter just informed me that the egg has to be standing straight up. Cannot be laying on it's side.

thats a good thing, i remember it is harder to break on the small end. all 3 of my kids had to do this, it was fun.

my son, the overachiever (overthinker?) made a serious harness of rubber bands and mesh material, and different layers of mesh under it to absorb momentum, each one designed to tear and fall to the next one. his did work, but it was very dependent on landing the correct way. it also took forever and lots of help getting the stuff made inside the box we used.

 

[guyver01]

i suggest reading this:

http://www.instructables.com/id/egg-drop-experement/

 

[ForumMaster]

there's an xkcd for everything...

 

[bonkers325]

5"x5"x5" box?

just embed it dead center of the box and fill it with gelatin.

 

[brblx]

My physics teacher in high school told us he did it by slathering a couple of dozen sheets of plastic wrap with peanut butter, the entire stack was maybe 6" high I think he said, but it absorbed the impact like kevlar.

This is different because it is being dropped in a cage, but as others have said, use something like peanut butter, marshmallow fluff, or a non-newtonian fluid.

you obviously don't want anything that would absorb impact like kevlar. you're slowing an egg, not stopping a bullet.

 

[her209]

 

[hanoverphist]

Then perhaps the student should fail. Experiencing the embarrassment of failure is likely to prevent the procrastination in the future right? Oh this is today's generation who simply don't care...... In any event by helping now the parent reinforces the notion that procrastination is OK.

There is a reason I'm not a parent.

the punishment afterwards for neglecting the project and not completing it in a timely manner is the difference between it being "OK" and "notOK". it is a good thing youre not a parent i guess, since you missed the actual lesson in helping and then punishing.

and for the record, im a major procrastinator for the most part. always have been, even when i would do the same thing in school. my mom didnt help me with my projects however, she just let me fail or work it out on my own.

 

[TuxDave]

Another method, look up "ooglick" or something like that.

Oobleck. I remember playing with that in middle school science class.

 

[Phoenix86]

Repost.