Given that an iron ball falls in glycerine contained in a jar where the viscous force F depends on terminal velocity V radius R of the ball and the coefficient of viscosity obtain and name the mathematical expression suitable for the relationship btw the parameter if the constant in this case is 6π units
F = C coef v^2 (some area)
if there is flow separation probably the cross sectional area is the important one pi r^2
if there is little flow separation then maybe surface areas 4 pi r^2.
coefficients for spheres are shown both ways
they may want you to say
F = (6 pi)coef of viscosity * v^2 r^2