PhysicsClass 10CBSE
Causes of friction
Interlocking of microscopic surface irregularities (asperities) — primary causeMolecular adhesive forces (van der Waals forces between contact surfaces)Normal force — greater pressing force = greater interlocking = more friction (f = μN)Nature of materials — rubber/concrete = high friction; ice/ice = very lowSurface deformation — soft materials deform to increase contact areaLubricants — reduce friction by creating a separating film