## What is Friction?

The most common resistive force we experience every day is called friction is caused by the contact of two rough surfaces.

## What is Viscosity?

Viscosity is just the friction between two fluid layers when the two layers move relative to each other.

Viscosity is kind of a special case of friction.

Friction and viscosity are two properties that matter a lot. Let us have a deep insight into the difference between viscosity and friction.

## Main difference :

Friction is used to refer to forces that resist relative motion, whereas viscosity refers specifically to resistive forces that occur between layers of fluid when fluids attempt to flow.

## Difference between viscosity and friction :

• Friction is due to the resistance of relative motion between two solid surfaces where viscosity is due to cohesion or adhesion between two surfaces.
• The viscous force depends on the velocity gradient and area of contact and frictional force independent of the area of contact and relative velocity.
• The force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding between them is called friction while the viscosity of a fluid is a measure of its resistance to gradual deformation through shear stress or tensile stress.
• Friction between solid matter does not depend on speed difference while friction in fluids depends on speed between adjacent layers by means of their viscosity.
• The viscosity of liquid decrease with increase in temperature, Where friction independent of temperature.

Similarity :
• Both properties came in to play whenever there is relative motion.
• Both oppose the relative motion.
• Both depend upon the nature of the surface.
• Both can be erased by intermolecular force.
You can also want to know the difference between related terms like the difference between viscosity and density.