Question

State Stokes’ law (without derivation) for a body falling freely inside a liquid. Defining

terminal velocity, derive an expression for the terminal velocity acquired by the freely

falling body inside the fluid. ​

Answer 1

Explanation:

When a body falls in a viscous medium, it carries with its layers of fluid which are in body's contact where as the layers of fluid in contact with the stationary surface remain almost at rest. The layers of fluid destroys the relative motion and motion of the body is thus opposed. The viscous drag increases with velocity of the body till viscous drag and upthrust of the body are together equal to the weight of the body which acts downwards.