Physics Ontology

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η\eta
Mechanics

Viscosity

Measure of a fluid's resistance to flow; used in Stokes' law.

SI unit

pascal second (Pa·s)

Dimension: [ ML−1T−1 ][\,M L^{-1} T^{-1}\,]

Other units

  • pascal second (Pa·s)

Order of magnitude

How values of viscosity span the physical world (in Pa·s, log scale).

Water (20 °C)
10-3 Pa·s
Honey
101 Pa·s
Pitch
2.00 × 108 Pa·s
Lower limit10-4 Pa·sUpper limit103 Pa·s

Appears in 1 equation

Stokes' Law
F=6πηrvF = 6\pi\eta rv