Raw and cooked eggs

Teacher had some raw and cooked eggs but couldn't tell which was which so we helped her.

If you spin a cooked egg it spins quickly and stops immediately if you put your hand on it.
This is like a child in a car with a seat belt on who stops as soon as the car does.

If you spin a raw egg it spins more slowly and stops for a second if you put your hand on it, but then continues spinning slowly.  This is like a child in a car with no seat belt on.  When the car stops suddenly the child keeps moving, often bumping his head on the seat in front or the windscreen.
This is a good test for raw and cooked eggs, and a good reminder for us to always wear our seat belts in the car!