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Physics Egg Drop

  1. Aug 24, 2005 #1
    I'm a senior in high school, and we were just assigned the famous egg drop project...

    Here are the rules/restrictions/guidelines that our teacher gave us:

    You will design a container for an egg that will keep the egg from breaking when dropped from a height of approximately 5 meters (we're dropping from the 2nd story window).

    We can use unlimited sheets of loose leaf paper, cotton balls, and scotch tape... These are the ONLY materials we can use for the entire project...

    -The design must allow easy opening and closing for egg inspection.
    -Before the container is dropped, it must fit into a 25-cm x 25-cm x 25-cm cube.
    -The egg must be raw, its shell uncoated.
    -The egg must survive the drop.
    -Designs with lower mass receive higher scores (i don't think this is an issue as much as actually getting the egg to survive LOL)

    So, how would you people design this container? I was thinking of possibly making a bowl out of paper just and cushion the inside with cotton balls.. on every side of the egg... and put a lid on it.. and on each side of the outside of the bowl... put a lot of folded paper.. so that it makes a look like an accordian on every side... to absorb impact...

    any input would be great

    How would you people design it?
  2. jcsd
  3. Aug 24, 2005 #2


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    Try building one made out of pistons. You can build a paper piston can't you? I mean, that's just one paper tube inside of another and instead of filling it with air, fill it with . . .
  4. Aug 24, 2005 #3
    what would a piston do filled with cotton balls?... and how was my initial idea?
  5. Aug 24, 2005 #4


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    Well Jacob, your bowl would/maybe work just fine. Also, stuffing the pistons with cotton some optimum way as yet undetermined would of course absorb the shock (as the innner piston compresses the cotton inside the outer piston) when the egg lands. I'm thinking these pistons all around the egg of course. Would look high-tech you know. Paint it, add some small fins and a nose cone and a little ladder for him to get out when he lands. :smile: Just a suggestion.
    Last edited: Aug 24, 2005
  6. Aug 24, 2005 #5
    can you draw me a diagram of some sort of that design? i'm having trouble visualizing it... if i have something to look at.. i'll get right to building it and trying it out =).... just email me at Jacobpm64@yahoo.com

    I'll need it as soon as possible.. we have to have most of it completed by tomorrow.. and the drop is on friday
  7. Aug 24, 2005 #6


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    Really, it's not the fall that hurts the egg, but the hard stop at the end.

    Your goal is to make the stop softer - there are two popular ways to do this:
    Slow down the fall (parachute)
    Soften the fall (use some kind of padding/crush zone).

    It's *extremely* likely that some sort of hybrid approach is going to be optimal.

    Over 5m it's pretty easy to make sure that the device lands in the right orientation, so that will probably be less work/material than if you padd it in all direction.

    One of the slickest egg drops ever was a very precise cardboard tube that had fins. When it hit the groud, the egg would slide down the inside to dissapate the energy. (The tube was designed for a particular egg.)

    Also, you can get 'free' padding material using air.

    The easiest design will almost certainly be a parachute. For that, it'll be an issue of having it unfold well if anything at all.
  8. Aug 24, 2005 #7
    again, all i can use is regular loose leaf paper... cotton balls.. and scotch tape..

    I don't think parachutes are possible with regular paper lol
  9. Aug 24, 2005 #8
    The piston idea sounds worth trying. Or perhaps you could build a 15cm truss for the egg to sit on, then when it landed it would crush the truss, hopefully absorbing the impact. By truss I mean a structure that would sit in the bottom of say, a paper box, designed out of triangular shapes. In between this truss structure you could insert cotton balls to increase the resistance of the truss when it hits the ground.

    Good luck, and make sure you try it out at home before the drop on friday, you want to know it works before you get to the drop.
  10. Aug 24, 2005 #9
    wow, two posts appeared in the time it took me to type up my response...your a popular guy.

    Anyway, I just read the post by NateG and his tube idea, and I had an idea combining that with the piston idea. If you could build a long tube (25cm tall is max u said?) but a tube that is quite sturdy, then you could build a capsule for the egg that is a tight fit into the tube. You seal the bottom of the tube, and when it hits the ground the air cushions the egg's capsule, kind of like a hydraulic.

    Of course, building a sturdy tube out of paper isn't easy, but I'm sure if you made the cylinder, you could build a box around it and reinforce the cylinder with paper beams (little cylinders). I'll sketch it in a minute and post it.


    Ok, it's not the greatest diagram but I hope u get what I mean. The "big cylinder" is the main chamber that the capsule sits in for the air cushion to act upon.

    The little paper cylinders, tubes, are reinforcements, and travel down the length of the tube keeping the form of the cylinder. If you try this please make them more precise than in my diagram they are all over the place.

    This is a top view:

    Attached Files:

    Last edited: Aug 24, 2005
  11. Aug 24, 2005 #10
    i'm just wondering why making a bunch of little paper tubes will provide more shock absorption than just loading the container with cotton like an easter basket and embedding the egg in it... i just want to know lol
  12. Aug 24, 2005 #11


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    Good grief! Parachutes are braindead easy:
    To make the canopy you simpy tape sheets together edge-to-edge.
    If you're feeling fancy, you can cut wedges out to make it arch, but it's not necessary.
    To hold the egg, fold a sheet of paper into a cone, cup or bag (all easy).
    Then attach the basket to the edges of the canopy using ribons of tape or paper.

    If you want a (moderate) challenge, use only paper.
  13. Aug 24, 2005 #12
    If you're talking about my diagram and the cylinder idea...those paper tubes aren't for shock absorption, they're to reinforce the cylinder so that air doesn't escape as easily (which it would do if the cylinder wasn't sturdy).

    If you're talkin about my trruss idea...well, I suggested making the paper truss and putting cotton balls in-between. The paper truss doesn't collapse as easily as cotton balls, so it would provide more resistance and there would be less chance of the egg striking the ground or 'bottoming out'. The cotton balls are still there to protect it though.

    If you're not referring to my post than forget what I said. lol
  14. Aug 24, 2005 #13


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    Sounds like others have given you ideas too. I don't wish to suggest mine is the best. Just an idea. It might take a while to design an efficient one. Ideally, you'd need to experiment to come up with a decent design. Perhaps a cube with the pistons coming out of each corner and egg in the middle. Make the cube out of rolled-up tubes as well. Might win for being the lightest weight too. :smile:
  15. Aug 24, 2005 #14


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    Here's a weird thought!

    What if you could build a sort of swing for the egg? The swing is somehow supported in an up position, but the supports are weak enough to collapse when the whole device hits the ground, and the egg starts swinging back and forth, unharmed.

    The whole thing might have to be too heavy, though.


    Or, you could design some sort of slide that leads into a circular corral. The idea being not to cushion the impact directly, but to turn the downward momentum into sideways momentum, and just let roll around until it stops.

    Or, the slide idea could be used just to give you extra room to slow the egg.


    Actually, I wonder if the whole downward into sideways momentum couldn't be put into good use: have the egg send a bunch of paper thingies shooting in all directions to bleed off the energy. Unlike the cotton, these things won't continue to take up space underneath the egg once they've been used!
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