# Stoke's Drag Constant

I'm trying to calculate Stoke's drag constant using the equation found here.

The system I wish to calculate it for is a mass oscillating vertically on a spring through air. The temperature is 25 degrees celsius. The area of the base of the mass is 4.9x10^-4 square metres.

I'm not sure how to find the 'fluid viscosity' in the linked equation, or what 'Stoke's radius' is.

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From where, MathsStudent, do You get the idea, that Stokes law is appropriate to Your "spring"? Did You check Reynolds Number? – Georg May 21 '11 at 10:24