Intro: Egg Drop Physics
The egg drop experiment can have many variations. This is the one I like best. I have used it for a number of years, made some adjustments along the way, and think it's finally time to share with you.
I use this project as a way to make the mathematics part of physics relevant to my 7th graders. They are calculating mass, speed, velocity, momentum, force, and acceleration and having fun at the same time. They have the freedom to design their own project but are constrained by the materials provided and the time allowed.
The materials are cheap and easy to acquire which is a recurring theme on my teacher budget (materials are on the next page).
I usually give students about 45 minutes of pure build time. This does not include the time taken to hand out materials. I usually hand out the materials and give them some planning time... then start the clock. Because my school has 45 minute periods, we can't do it all in one class period. I force them to build and test in two.
I have an area to drop that is 5.3 meters. You will want to find an area that is at least 4. The higher the better!
*The new national science standards, if your state chooses to adopt them, will place greater emphasis on the process and application of topics than on recall. This is a simple, yet effective way to asses what they know and are able to do (and aligns perfectly with the motion and forces standards).
Step 1: Title, Introduction, Materials, and Methods
How does the design of an egg contraption protect an egg from the combined forces acting on it when subjected to a drop of 5.3 meters?
a. Background - In class, the topics of speed, velocity, resultant velocity, acceleration, and momentum were explained and mathematical calculations were performed.
b. Purpose - This experiment is designed to review these forces by completing an egg drop lab.
c. Hypothesis - If an egg is dropped from a height of 5.3 meters and the egg shell must not crack, then the egg must be well protected from outside forces acting on it.
d. Prediction - Egg contraptions with the most speed and therefore the most velocity, acceleration, momentum, and force, will have the greatest chance of breaking.
a. Materials: Teacher should supply a balance, a good place to test the contraption, a way to measure the height of the drop in meters, and a stopwatch.
1 egg (I don't always hand these out right away)
5 popsicle sticks
5 straws (I like bendy straws but it doesn't matter)
5 rubber bands
2 sheets of paper
100 cm of string
100 cm of masking tape
b. Methods -
1st: Create a detailed drawing of what you plan to build.
3rd: Build a contraption that can protect an egg from a fall of 5.3 meters
4th: Find the mass of the contraption (with the egg)
5th: Test the contraption (calculate time of fall with stopwatch)
6th: Calculate speed, velocity, acceleration, force, and momentum
7th: Analyze results
8th: Create a detailed drawing of what you actually tested.
Step 2: A Fun Twist
After students start to build, I give them the option of trading materials with the "store".
Here is a short skit of what an exchange might sound like...
Student: What can I get for 3 popsicle sticks?
Teacher: What do you need?
Student: Another sheet of paper.
Teacher: That will cost you 4 popsicle sticks and a straw.
Student: Let me go ask my lab partner... You drive a hard bargain, but we'll take it!
Teacher: Make sure you record any transactions for when you write your formal lab reflection.
It's that simple. You can base what you trade on how you're feeling that day, the after market value, or how much you like the student. I'll admit that I even caved when a group had no materials left to trade but offered me a sweet pen. Bribery got the best of me that day (but I still have the pen :).
I also give students .5 point back for each whole, unused material they can turn in at the end.
Step 3: Lab Reflection
Procedure Continued (written in paragraph form with NO personal pronouns) It should read much like a cookbook.
Describe how the contraption was assembled. Were any materials exchanged? If so, which ones, how many, what for? Were any materials omitted?
Results: Provide an account of what happened during the experiment.
Include the mass of your project with the egg. Include the speed of the project and show all the math needed to calculate the results. Calculate the velocity, momentum, acceleration, and force of your contraption. All mathematical calculations should be written neatly on a separate sheet of paper and attached to the lab.
Conclusion: This is the most important part of the lab! Restate the hypothesis first
Include the following: What features did the contraption have to help protect the egg? What did the egg look like after impact? What worked (either in your project or others)? What did not work (either in your project or others)? List three things you would do differently (in bullet form) if you could do this project again.