Viscosity
What it is
Viscosity is the opposition of fluids and gases to flow. Highly viscous liquids
such as molasses flow slower than less viscous fluids such as water.
History
William Froude (1810-1879) experimented on the resistance of fluids to motion.
Ernst Mach (1838-1916) studied resistance to gas flows.
George Stokes(1819-1903) studied viscosity by observing the movement of tiny
spheres falling through liquids.
Common equations
force = viscosity * area * velocity / distance
viscosity = density * velocity * length
Units
poise
centipoise
lb weight per in^2
gm weight per cm^2
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