Answer:
Step-by-step explanation:
Friction between two surfaces is caused by the contact between them. When two surfaces interact, the roughness of the surfaces combine with the contact force to create a force that resists the motion of the surfaces. When two surfaces are moving relative to each other, the contact force must overcome the friction force in order for the surfaces to move.
Friction can be reduced by either reducing the contact force, or by making the surfaces smoother. One way to reduce the contact force is by using a lubricant, such as oil or grease, to reduce the amount of contact between the surfaces. This reduces the force of friction and allows the surfaces to move more easily. Another way is to make the surfaces smoother, which reduces the amount of roughness and therefore reduces the friction. This can be done with sandpaper or other abrasive materials.