| Friction is the resistance between
two surfaces that are in contact with each other. |
|
There is friction between a car
tyre and the road with which it is in contact. |
|
 |
| |
|
|
|
|
| Friction can be reduced between two
surfaces. |
|
Blades of ice skates are sharp and
able to slice through the surface of the ice, leaving a small
water channel, so friction is lessened. |
|
  |
| |
|
|
|
|
|
|
Oil can reduce friction between rotating
cogs. |
|
 |
| |
|
|
|
|
| Sometimes we want to increase friction
between two surfaces. |
|
When we want to slow a bicycle
quickly, we need to have a lot of friction between the brake
blocks and the wheels they touch. |
|
 |
