Here are some examples of contact forces:
* Normal force: The force exerted by a surface on an object in contact with it, acting perpendicular to the surface. (e.g., the force of the ground pushing up on your feet)
* Friction: The force that opposes motion between two surfaces in contact. It can be static (preventing motion from starting) or kinetic (opposing motion that is already occurring). (e.g., the force that slows down a sliding book on a table)
* Tension: The force transmitted through a string, rope, cable, or similar object when it is pulled taut. (e.g., the force in a rope pulling a wagon)
* Applied force: A force applied directly to an object by a person or another object. (e.g., pushing a box)
* Air resistance: The force exerted by air on a moving object. (e.g., the force that slows down a falling object)
In contrast, non-contact forces act between objects that are not touching, like gravity and magnetism.
