Friction is the force that opposes the relative motion or the tendency of such motion of two surfaces in contact. It acts in the direction opposite to the direction of motion.

Characteristics of Friction

1.Opposes Motion: Friction always acts to oppose the motion of an object.

2.Contact Force: Friction arises due to the contact between two surfaces.

3.Depends on Surfaces: The amount of friction depends on the nature of the surfaces in contact and how much they are pressed together.

Types of Friction

1.Static Friction

Acts on objects that are not moving.