What Is Frictional Force?

Force of friction is the force that opposes the motion of an object when it comes into contact with another surface. For example, walking on rough surfaces becomes difficult because the surfaces grip each other.

🧩 How Is It Formed?

-Surfaces are microscopically rough; their irregularities interlock and hinder motion.

-Additionally, as the pressure (normal force) exerted by the object on the surface increases, the force of friction also increases.

✨ What Are Its Types?

Static friction

-This is the friction that prevents an object from starting to move when it is at rest.

-This force must be overcome to initiate motion.

Kinetic (dynamic) friction

-This is the force that opposes motion when the object is already moving.

-It is generally smaller than static friction.

🧮 Formula for Force of Friction

f = μ · N

-f: force of friction

-μ: coefficient of friction (depends on how rough the surfaces are)

-N: normal force exerted by the surface

This formula provides a simple way to calculate friction.

🧽 How Does It Appear in Daily Life?

-Walking and running: Friction between our shoes and the ground allows us to walk without slipping.

-Stopping of a ball: A rolling ball eventually comes to a stop due to friction with the ground.

-Car brakes: When braking, friction between the tires and the road causes the vehicle to stop.

-Writing with a pen: Friction between the pen and paper enables us to write.