Sit cross-legged on a swivel chair. Hold a heavy book in each hand. Have a friend spin you around. Stretch your arms out to the side, then bring them back in. What happens? You have become a gyroscope
Make a gyroscope for the class. Find an old bicycle wheel, and have a parent volunteer attach handles to the hub. Hold the handles tightly. Have a friend spin the wheel. Try to twist the wheel. What happens? Sit cross-legged on a revolving chair or an old-fashioned piano stool and do the same thing. What happens?
Which will spin longer, a hard-boiled egg, or a raw one? Why? Test it.