Welcome back! If you see a raw egg and a hard-boiled egg side by side, how can you tell which one is cooked? (Without breaking them open, of course!) You’ll learn how to do that, as well as learn science vocabulary like “inertia.” You can also just eat a snack of an egg. Just make sure you know how to pick the cooked one!
Materials:
- Two eggs – one raw and the other hard-boiled. (I’ll explain how to cook one if you don’t know).
Procedure:
- Hard boil an egg; make sure you get your parents’ permission. Fill a small pot with water so that it covers up an egg. You might want to cook two eggs because sometimes an egg can crack, etc. Boil the water over medium-high heat. After it starts boiling, cover the pot and remove from heat. Let it cook for 10-12 minutes. After that, rinse the egg in cold water. Now you’re ready for some science!
- Put two eggs, one cooked and one raw, next to each other on a table or other flat surface. Don’t do this too close to the edge or they might roll off!
- Spin the raw egg on its side (not on the end) so that it goes pretty fast. Stop the egg from spinning by QUICKLY stopping it and then IMMEDIATELY letting go. If you hold onto the egg too long, it won’t work!
- Do the same thing for the cooked egg and notice the difference in what happens after you let go.
Explanation:
You should have noticed something strange happen when you did this. The raw egg starts to spin again after you stop it and let go, whereas the cooked egg stops and then stays stopped. Why is that?
If you know about Newton’s Laws of Motion, he described that an object in motion will stay in motion. This is a measure of an object’s inertia. So, when you spin the raw egg, both the shell and the yolk are moving, BUT when you stop the shell, the liquid yolk on the inside keeps moving, and so it starts spinning up again. The object in motion stays in motion!
However, when you stop the shell of the cooked egg, the whole thing stops since the liquid is all cooked to be solid.
Going further:
Sometimes the best way to learn something is to teach it! Show your parent, a sibling or a friend this trick. And remember, clean up after yourself and make sure you put the raw egg back in the fridge when done.
LOOKING FOR MORE science experiments? Find them here!
About the author:
Steve Davala has been teaching math and science to middle and high schoolers since 2000. He writes books, plays music, carves wood and he loves learning new things. Ask him a question at steve.davala@gmail.com.
