Liquid by the external force, the internal frictionbetween the nature of molecules, called the viscosity. The nature of thisinteraction inside a liquid is called the viscosity of a liquid. Dynamicviscosity, also known as absolute viscosity, that is, the area of each 1cm2 and1cm2 away from the two-layer liquid for relative movement, the resultingfriction, known as the dynamic viscosity. Kinematic viscosity, also known asdynamic viscosity or internal friction coefficient. Is the ratio of the dynamicviscosity η of the liquid to the liquid density ρ at the same temperature, denoted by the symbol ν

ν = η / ρ. Kinematic viscosity at temperature t0C ν that due to the dynamic viscosity of the order of g / cm· s, the density of the order g / cm3, so the kinematic viscosity due to theunit: cm2 / s or mm2 / s. Kinematic viscosity is the internationally acceptedviscosity.