How do you tell the difference between a hard-boiled egg and a
raw egg without cracking them? Can you spin an egg and make it
stand on end?
What you need:
- Hard-boiled egg
- Raw egg
- Kitchen table
- Marker pen
How to:
Ask an adult to hard-boil the egg for you.
- Label the hard-boiled egg with a H. Label the raw egg with a
R.
- Spin both the eggs on the kitchen table. What do you
notice?
- Spin both the eggs again. stop them by putting your finger on
them lightly. What do you notice?
- Put the raw egg to one side. Spin the hard-boiled egg again and
make it spin very fast. What do you notice?
The hard-boiled egg should spin on its end!
What's happening?
Now you can tell the difference between hard-boiled eggs and raw
eggs, just by spinning them!
Hard-boiled eggs are easy to start spinning and easy to stop
spinning.
Raw eggs are harder to start spinning and keep turning a little
bit when you try to stop them.
Why?
Hard-boiled eggs are solid inside. In the raw egg, the liquid
inside the egg slides about and stops the egg from spinning as
fast.
When you stop the hard-boiled egg, it stops quickly. When you
stop the raw egg, it keeps turning a little bit. You have only
stopped the shell, not the liquid inside. The liquid is still
moving, which causes the shell to keep turning.
Hard-boiled eggs will spin on their end if you spin them fast
enough. The egg saves energy by spinning on its end and making a
smaller circle.