# Difference between revisions of "Viscous drag"

From Soft-Matter

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<math> F_{drag} = -6\pi a \eta v</math> | <math> F_{drag} = -6\pi a \eta v</math> | ||

− | where a is the radius of the sphere, | + | where a is the radius of the sphere, η is the viscosity of the fluid the sphere is in and v is the velocity of the sphere. |

## Latest revision as of 19:20, 4 November 2009

If an object moves slowly through a liquid, it will experience a viscous drag which is approximately proportional to the velocity. For a sphere falling through a liquid in a velocity regime where viscosity is the dominant effect and turbulence can be neglected, the viscous drag is

<math> F_{drag} = -6\pi a \eta v</math>

where a is the radius of the sphere, η is the viscosity of the fluid the sphere is in and v is the velocity of the sphere.