For the friction force to exist, there must be two surfaces in contact, this type of force is produced from the small imperfections that usually appear on the surfaces that are in contact.

10 Examples of Frictional Force

1. • When people who are fat rub their legs when walking and this causes irritation.
   • When brushing with the branch of a tree and it tends to hit hard.
   • When you are painting and rubbing the paintings inadvertently damaging your work of art in this way.

1. When you rub your new shoes with a tube full of grease, they automatically get dirty.
2. When he leans against a wall and the friction with it causes you to stain your shirt.
3. A two cars rubbing on the public road can cause an accident.
4. When walking and rubbing against an object, this can cause an accident and form a bruise on the part of the body where the rubbing occurred.
5. Roughly brushing against a person this can cause a strong blow.
6. When touching a match with the box, it automatically generates a combustion with which it ignites.
7. By touching two stones with force, this causes them to produce heat to the point of igniting.
8. When people feel very cold, they rub their hands, this enables circulation to be activated.
9. When the sole of the shoes are thick, these with the friction with the floor usually produce an uncomfortable sound.
10. The friction that exists between two people when they are in love and they kiss the friction of the skin alters the emotions.
11. The friction that occurs between the wind and the skin when riding a motorcycle.