Egg Crush Physics




About: I'm a middle school science teacher going on 15 years in the classroom. I've taught 6th, 7th, and 8th graders. I'm constantly looking to improve my instruction and Instructables is one of the places I sear...

Let's keep it simple!

In this project, students must build a contraption that can protect an egg from being crushed.  The only materials they are allowed to work with are flat wooden toothpicks and wood glue.  The force being applied to the egg contraption is in the form of a 5 gallon bucket falling from above.  If you're a teacher friend, continue reading below.  If not... don't bother with the reasons for the experiment and skip to the fun part.

You can check out the videos on step 4 for a better idea of what happens to the final product!

Objectives: Student will demonstrate ability to...

1. plan and build a device to protect an egg from forces acting on it.
2. identify the forces acting on their egg contraption and build accordingly.
3. compare and contrast what worked vs. what didn't work.
4. reflect upon what they would do differently.
5. collaborate in small groups throughout the process.
6. calculate the forces acting on their egg (momentum, force, acceleration, speed, velocity)
7. identify where Newton's 3 laws of motion can be observed in the schematic of the experiment. 

This lesson can be easily differentiated.  (less toothpicks, less time to build, increased mass in the bucket, higher drop height... you get it)  

Students can work in pairs or go at it alone.  I do not recommend bigger groupings.

Step 1: Materials

The materials for this project are cheap and easy to acquire.  

For the build you will need...
a. 200 flat wooden toothpicks. (I found the mass of 200 toothpicks is 11.3 grams.  I measured out 11.5 because some toothpicks are bound to be bent / broken / too skinny... You can have the kids count them out after you hand them out if they think you shorted them.  This way you don't have to take time to exchange bad toothpicks)
b. Wood glue
c. Wax paper
d. Graph paper
e. 3.5 oz bathroom cups (I like plastic better because they hold up for multiple uses)

plastic Easter egg, ruler, scissors

For the test you will need...

a. 5 gallon bucket (1)
b. Eggs  (One for each project built)
c. A pulley (optional... just helps decrease friction)
d. Rope (length depends on how high your ceiling is)
e. mass to add to the bucket (I used textbooks)
f. a meter stick or yard stick to measure how high the bucket is when you drop it.

Step 2: The Pre-build

Here are the first three things I tell my students.

1. Imagine where the force is coming from.  Where will you need the most support?  Hint: A roof will NOT help protect your egg.

2. This is a three dimensional project.  (You need to plan out the walls, build the walls laying flat on the table, let the walls dry, and then stand the walls up and glue them together.  Make sure you check out the picture that shows what NOT to do.)

3. Don't waste your time and wait for toothpicks to dry.  There is always something you can work on.  

I start class with a warm up (do now) on one of Newton's Laws and how it relates to the project.  After reviewing student generated responses, they can get their project and start / continue building.  They will need a refill on glue at the start of class each day.

Step 3: The Build

When building it is important to do the following...

Work on top of the wax paper.
Glue toothpicks together.
Let toothpicks dry.
Protect egg at all costs!

Below are some ideas my students came up with.

Step 4: Testing Time!

This is how I do it.  You are free to modify.

1. Place the egg contraption beneath a 5 gallon bucket with a predetermined mass (I use 2 textbooks in the bucket).
2, Add some construction paper beneath the contraption to make clean-up easier.
3. Gently place the bucket on top of the contraption. 
4. Raise the bucket six inches and drop it on the contraption.
5. If the egg is still in tact, raise the bucket 12 inches and drop it on the contraption.
6. If the egg is still unscrambled, raise the bucket 18 inches and drop again. 
7. I usually stop at 18 inches.  If the egg survives from this distance, the project in my mind is a success.

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    19 Discussions


    5 years ago on Introduction

    I do not get why you make cubes, wouldn't piramides or "pillars"(=cilinders with wider top and botom than the middle) work better. I think they would as they channel the energy and force to the table skipping the egg. Could you explain this?


    5 years ago on Introduction

    I alternate with my Physics 20 class; building one egg drop/crush using toothpicks first semester, then in second semester the next class uses Fettuccine pasta for the build. Ground rules for Fettuccine pasta give specific lengths that are allowed for the build. I don't usually need to 'police' that rule as students being so competitive make sure no group breaks the length rules.

    2 replies

    Reply 5 years ago on Introduction

    Sounds like a fun lab. What do they use to "glue" the fettuccine together? Bringing competition into the mix is a great idea. You should publish an ible on the lab. Thanks for the comment!


    Reply 5 years ago on Introduction

    Low temp hot glue. Tried white glue but the time it takes to dry causes the pasta to soften as well. Students have also built bridges which are then hung with weights to test strength. Best one so far was a 27 cm long box-style bridge and held weights up to 1.6 kg.
    Students are given a 'kit' containing pasta(300g), hot glue(15 sticks) and mini hot glue guns. Bridge building or stress vs. load concepts are discussed in the first half of period then they brainstorm for second half. At the end of that block they must present a finished diagram with measurements for approval. Next block (blocks are uniform at 90 min each) they build. Students are given an additional five periods to tweak their projects--the last 20 minutes of class. They may also do so after school or at lunch. If they require more supplies, they may trade amongst themselves but nothing comes in from the outside, this is well policed by students. All bridges are tested by adding weights hung from the centre of the bridge which itself is suspended between a stack of textbook, usually 20 cm off the bench surface. Weights are available throughout the project for testing. Egg drop is tested from the second floor into the rotunda area at the front of our school. As a courtesy to Facility, each competitor is given a green garbage bag to house the egg contraption.
    Hadn't thought about making an 'ible. Short photos as our Board has massive paperwork if we want to photo students but I may have some with only the projects in them.


    5 years ago

    I noticed that u use the might cinders tri sided pencils.... those are my favorite!!!!


    7 years ago on Introduction

    my 8th grade project was to make a bridge constructed of toothpick-length square sticks and then we hung weight-lifting weights from a rope under the bridges to see how much weight they would sustain. mine was the best design of its category and won first. then we placed all the categories into a contest and mine won either somewhere tween 2nd + 4th place. i love construction projects like this!!


    7 years ago on Introduction

    I think I would probably build a cylinder by gluing the toothpicks together vertically to make a solid wall and then two flat panels on the top and bottom, to make a sort of egg in a wooden barrel. If the rules permitted it I think I would also glue the cylinder to the egg.


    7 years ago on Introduction

    That's fantastic. When I was in school we did dropping eggs and making protectors. But this has so much more potential for mess!

    1 reply

    I had an egg drop assignment in school too.

    We had to make something to drop the egg into from the stairs. It was set up like a contest, the height the egg was dropped from was divided by the height of the egg drop container.

    I made mine from a very shallow cardboard container filled with sand and I won! My egg only cracked because it was dropped and didn't land in the box.

    Some other kid dropped his in a bowl of honey of honey but his container was much taller than mine. We were supposed to drop from incrementally higher steps but he skipped them all and went to the top and got lucky. The teacher gave us both extra credit but I still say mine was more legit :|


    7 years ago on Introduction

    Pyramidal / tetrahedron looks better to me(in my imagination).



    Reply 7 years ago on Introduction

    I love your greenhouse. Is that your property in the picture? I wish I had that much space for my garden!


    Reply 7 years ago on Introduction

    :-) My front garden in the frame work pictures but the built pictures are on our 1 acre allotment patch.


    7 years ago on Introduction

    Very nice! Liked it.. wish we had the same experiment at school when I was young :D