Contact force

A contact force arises when interacting bodies physically touch. Friction, normal force, tension, and drag are common examples.

Newton's laws of motion: Three classical laws relating forces, mass, and motion. They describe how contact forces change an object's motion.
Tension (physics): A pulling force transmitted through a taut rope, cable, or similar connector. A taut connector transmits contact forces along its length.
Non-contact force: A force that acts without the interacting bodies physically touching. It is the direct opposite of a force arising at a physical interface.
Static equilibrium: A state in which an object's acceleration is zero because the net force and torque vanish. Contact forces balance other forces when objects remain at rest.
Force: An interaction that changes or tends to change an object's motion. Contact force is one broad way forces arise.
Drag (physics): A resistive force exerted by a fluid on an object moving through it. Fluid molecules transfer momentum through contact with the object's surface.
Gravitational force: The mutual attraction between masses, described classically by Newton's law of gravitation. Gravity acts across distance rather than through a touching interface.
Inclined plane: A flat surface set at an angle to the horizontal. Its normal force and friction determine how an object slides or stays put.
Free-body diagram: A diagram showing an object and the external forces acting on it. It represents contact forces as arrows acting at interfaces.
Elasticity (physics): The tendency of a material to recover its shape after deformation. Elastic deformation at touching surfaces underlies many support forces.

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