Derive Stoke's law dimensionally.
Suppose a spherical body of radius r moves at a speed v through a fluid of viscosity ?. The viscous force Facting on the body is given by,
F = 6 ? ? r v
Actual derivation of Stokess viscous drag theorem from definition of viscosity is beyond the scope of XII physics however following is a proof based upon dimensional analysis.
Given k = 6?
Viscous force on a small spherical ball of radius r moving with a velocity v in an infinite sea of liquid of viscosity ? is found to be dependent on r, v and ?.