Yo-yo
device · 500 BC · Ancient world
A disc on a string.
What it is made of
- Two yo-yo halves — has part. Flywheel discs.
- Axle — has part. The axis between the discs.
- Rope — has part. A thread.
Principles and materials it uses
- Angular momentum — uses. Rotation.
- Conservation of energy — uses. Potential → kinetic energy.
- Clay — is made of. Greek yo-yos were terracotta.