Friction & Tension | Types of Friction

Friction 

Friction is a force that opposes motion between two surfaces that are in contact with each other. It arises due to the roughness of the surfaces and the interlocking of their irregularities. Frictional force always acts in a direction opposite to the direction of motion or the direction of applied force.

 

Example: When you try to push a heavy object across the floor, it resists your efforts due to friction. Similarly, the brakes on a car use friction to slow down or stop the car.

Types of Friction

There are several types of friction:

 

Static Friction: This type of friction exists between two surfaces that are not moving relative to each other. It is the force that must be overcome to start an object moving.

Example: A book lying on a table remains at rest due to static friction.

 

Kinetic Friction: This type of friction exists between two surfaces that are moving relative to each other. It is the force that opposes the motion of an object that is already in motion.

Example: When you slide a book across a table, the kinetic friction between the book and the table opposes its motion.

 

Rolling Friction: This type of friction exists when an object rolls over a surface. It is usually lower than kinetic friction because there is less contact between the surfaces.

Example: A ball rolling on a surface experiences rolling friction.

 

Fluid Friction: This type of friction exists when an object moves through a fluid, such as air or water. It is also known as drag.

Example: A swimmer moving through water experiences fluid friction.

 

Internal Friction: This type of friction exists within a substance or material, such as the friction between molecules in a fluid.

Example: When a fluid flows through a pipe, there is internal friction between the layers of fluid.

 

Tension

Tension is a force that is transmitted through a string, cable, or wire when it is pulled tight by forces acting on both ends. It is always directed along the length of the string, cable, or wire and its magnitude depends on the amount of force applied to the ends.

 

Example: When you pull a rope tied to an object, the tension in the rope increases as you apply more force to pull the object towards you. Similarly, the strings of a guitar or violin are under tension when they are tuned, which allows them to produce sound when they are plucked or bowed.