Module 2: Friction

• Angle of Friction: The angle between the resultant of the frictional and normal forces to the surfaces in contact at the moment of impending sliding.
• Angle of Repose: The greatest angle to the horizontal which can be made by an inclined plane before an object resting on it would start sliding down the slope.
• Coefficient of Friction: The ratio of the frictional and the normal force between two surfaces in contact when sliding motion is about to occur.
• Friction: The resistance to sliding motion between two solid surfaces in contact with each other.
• Angle of Repose = Angle of Friction
• The theory behind friction is: Adhesion or Interference