Friction occurs because no surface is perfectly smooth. Rougher surfaces have more friction between them. Heavier objects also have more friction because they press together with greater force. Friction produces heat because it causes the molecules on rubbing surfaces to move faster and have more energy.
source:
https://flexbooks.ck12.org › lesson
https://flexbooks.ck12.org › lessonFriction | CK-12 Foundation
When two surfaces slide over one another the tiny bumps push on each other. Friction causes a force on a surface which is in the opposite direction to its motion. Friction can be reduced by the application of lubricants.
Answers & Comments
Friction occurs because no surface is perfectly smooth. Rougher surfaces have more friction between them. Heavier objects also have more friction because they press together with greater force. Friction produces heat because it causes the molecules on rubbing surfaces to move faster and have more energy.
source:
https://flexbooks.ck12.org › lesson
https://flexbooks.ck12.org › lessonFriction | CK-12 Foundation
Answer:
When two surfaces slide over one another the tiny bumps push on each other. Friction causes a force on a surface which is in the opposite direction to its motion. Friction can be reduced by the application of lubricants.