Across
- 2. surfaces with oil,grease or graphite
- 4. irregularity of surfaces
- 6. spherical or cylindrical object
- 7. SI unit of force
- 8. the force opposing the object in motion
Down
- 1. the resistance an object encounters when it slides over a surface
- 3. rounded in the front and narrow at the back
- 5. fluid friction
- 8. push or a pull