Across
- 4. brilliant Greek mathematician
- 6. a bar that goes up and down over a point
- 8. a wheel with a groove; pulling down on rope lifts something
- 9. circular band made of rubber
Down
- 1. two inclined planes put back to back
- 2. any device that changes the amount of force needed to do work
- 3. an inclined plane wrapped around a cylinder or cone
- 4. rigid bar that's inserted through a hole in a wheel
- 5. the point at which a lever rests
- 7. a flat surface