Under what conditions, the velocity of a body falling in a medium (i) increases with time (ii) becomes constant with time (iii) becomes zero with time.

Explanation

The velocity of a body falling in a medium.
(i) Increases with time till the gravity pull on the body is more than the viscous force plus buoyant force of medium acting on body.
(ii) becomes constant with time when gravity pull on body is equal to viscous force plus buoyant force of medium acting on body.
(iii) becomes zero with time if body comes to rest in the medium . it will be so if the density of body is equal to the density of the medium.