Sari on Science
An Eggceptional physics party trick.
April is an eggcellent time of year to try this fun physics party trick. If you’re ready to get cracking, here’s the challenge: Do you think you can drop an egg into a glass of water without touching the egg or breaking it? Don’t be chicken—it can be done! And, I’m not yolking around.
Here’s what you need:
1 tall drink glass
Water (enough to almost fill the glass)
1 cardboard toilet paper tube
1 metal pie pan
1 egg
Directions:
Find a clear workspace free from breakables to set up this experiment—a cleared kitchen island or dining table are ideal.
Fill the glass about three-quarters full with water and set on workspace.
Set the pie pan on top of the glass in the same orientation as you would use to hold a pie.
Place toilet paper roll vertically (up-and-down) on top of pie pan, centered over the glass.
Balance an egg on its side on top of the toilet paper roll.
Hold your dominant hand about 8 inches from the side of the pie pan, with your palm facing the set up materials.
Quickly and forcefully smack the edge of the pie pan and pull your hand away. The pie pan will travel so be sure no one is standing in its way!
What’s Happening?
Make your observations first—what happened to the egg? When you use your hand to apply force to the pan, energy transfers to the pan, making it move. As the pan travels across the rim of the glass, the pan catches the edge of the toilet paper roll, pulling it out from under the egg. There is very little friction between the shell of the egg and the toilet paper roll, so the only force that really acts on the egg is gravity, causing the egg to fall straight down — safely into the glass of water. Now what? Consider, what would happen if you used a taller paper tube like a paper towel roll? Try it to find out! Or, take the super egg challenge: Try using a cookie sheet or lunch tray instead of a pie pan and stack multiple glasses underneath. How many eggs can you get safely into their glasses at once?
