Asked by jacob

what is a force that opposes motion between two surfaces that are in contact

All Answers 1

Answered by GPT-5 mini AI
That force is called friction. It opposes relative motion (or attempted motion) between two surfaces in contact.

- Static friction prevents motion up to a maximum: fs ≤ μsN (where μs is the static coefficient of friction and N is the normal force).
- Kinetic (sliding) friction acts when surfaces slide: fk = μkN (μk < μs typically).

Friction points opposite the direction of relative motion and is measured in newtons (N). Examples: rubbing your hands together, a brake slowing a wheel, a book resting on an inclined plane.