where , r = radius of the body , V = terminal velocity and η = coefficient of viscosity .
This is called Stoke ’ s law .
where , ρ = density of body , σ = density of liquid , η = coefficient of viscosity of liquid and , g = acceleration due to gravity 1 . If ρ > ρ0 , the body falls downwards . 2 . If ρ < ρ0 , the body moves upwards with the constant velocity . 3 . If po << ρ , v = ( 2r 2 ρg / 9η ) Importance of Stoke ’ s Law
1 . This law is used in the determination of electronic charge by Millikan in his oil drop experiment .
2 . This law helps a man coming down with the help of parachute .
3 . This law account for the formation of clouds .
Flow of Liquid
1 . Streamline Flow The flow of liquid in which each of its particle follows the same path as followed by the proceeding particles , is called streamline flow .
2 . Laminar Flow The steady flow of liquid over a horizontal surface in the form of layers of different velocities , is called laminar flow .