frictional resistance

Frictional resistance is the force that opposes the motion of an object moving across a surface or through a fluid. It results from the contact between surfaces or particles, where microscopic unevenness and interactions cause resistance. For example, sliding a box across the floor requires effort because friction pushes back against the movement. Similarly, moving through water or air encounters resistance, called drag. Frictional resistance depends on factors like surface roughness, materials, and the speed of motion. It plays a vital role in everyday activities, machinery operation, and transportation systems by affecting how easily objects can move or be moved.