Friction
Summary: Friction is a contact force that opposes motion between surfaces. Tags: concepts physics forces Created: 2026-04-22 13:10:04Z Last Updated: 2026-04-22 13:10:04Z
Content
Friction acts opposite to movement and can reduce speed, generate heat, and wear materials. Rough surfaces generally produce more friction than smooth surfaces.
Friction can be useful (grip for walking, braking) or unhelpful (energy loss in machines). It can be reduced by lubrication, smoothing surfaces, or changing design.