જ્યારે પદાર્થ સપાટી પર ગતિ કરતો તો તે ઘર્ષ

The objects have a relative motion between the surfaces which could be a body moving over a static surface, a static body on a moving surface, or both are moring but with different relative velocities. The term for this case is related to the term kinetic energy and is often called dynamic friction.