Friction

When surfaces move past each other, they offer resistance. This resistance is called friction.

Friction provides traction, which lets us walk without slipping. It plays an important role in our everyday lives:

• Holding a cup of tea or a chemistry book requires friction.

However, friction also has drawbacks:

• A lot of engine power in automobiles is wasted due to friction.

Factors Affecting Friction

• Surface roughness: If the surface is rough, friction increases.

• Surface smoothness: If the surface is smooth, friction decreases.

Friction is caused by irregularities in the structure of surfaces. When one surface moves over another, the irregularities get entangled, giving rise to friction.

• Higher irregularities → Higher friction

Types of Friction

1. Static Friction

   • Acts between surfaces that are not moving relative to each other.

2. Sliding Friction

   • Produced when two objects start sliding against each other.

3. Fluid Friction

   • Occurs when objects move inside a fluid, such as water or air.

   • Also referred to as viscosity.

4. Rolling Friction

   • Produced when a ball or object rolls on a surface.

Each type of friction is different and depends on the motion and interaction of the surfaces involved.