Frictional Force

Friction is a force that resists the relative motion or tendency of such motion of two surfaces in contact. It is caused by the irregularities on the surfaces and the intermolecular forces between the molecules of the materials in contact.

Types of Friction:

1. Static Friction: This is the friction that resists the initiation of motion between two surfaces that are in contact with each other and are not moving relative to each other.
2. Kinetic Friction: This is the friction that resists the motion of two surfaces that are moving relative to each other.

Factors Affecting Friction:

• Nature of Surfaces: The roughness or smoothness of the surfaces in contact influences the amount of friction produced.
• Normal Force: The force exerted perpendicular to the surfaces in contact affects the frictional force. The greater the normal force, the greater the frictional force.
• Types of Motion: Frictional force depends on whether the surfaces are at rest or in motion.

Applications of Frictional Force:

• It is essential for walking, driving, and other forms of locomotion.
• It is crucial in the operation of brakes in vehicles and machines.
• It helps in the gripping of objects and prevents slipping.

Study Guide:

1. What is frictional force?

Frictional force is the force that resists the relative motion or tendency of such motion of two surfaces in contact.

2. What are the types of friction?

Static Friction, Kinetic Friction

3. Name three factors that affect friction.

Nature of Surfaces, Normal Force, Types of Motion

4. What are the applications of frictional force?

Walking and other forms of locomotion, Operation of brakes in vehicles and machines, Gripping of objects and prevention of slipping