2. Friction

3. 1. What is friction? It is a kind of contact force It forms between two surfaces that move over each other Friction

4. Friction exists between the wood and the bench, slowing down the motion of it. Example friction direction of motion of wood

5. 2. Uses of friction Rough surface to give a firm grip on the ground Friction

6. Deep grooves on tyre surface to help cars move on slippery surfaces Friction

7. Braking system: brake pad rubs against the wheel to slow down bicycle Friction

8. 3. Ways to reduce friction Friction is reduced if the surfaces are lubricated with oil or water Friction

9. Friction in liquids and gases is reduced if an object is streamlined in shape Friction

10. Friction is reduced in rolling e.g. roller skates Friction

11. Friction is reduced by supporting the moving object on a layer of air e.g. hovercraft Friction