Which of the following option correctly describes the variation of the speed ` ` and acceleration `'a'` of a point mass falling vertically in a viscous medium that applies a force `F=-kv`, where `'k'` is constant, on the body?
(Graphs are schematic and drawn to scale)

Options

A.
B.
C.
D.

Answer

C

Explanation

When a pint mass is falling vertically in a viscous medium, the medium or viscous fluid exerts drag force on the body to oppose its motion and at one stage body falling with constnat terminal velocity.