Question

A spherical ball is dropped in a long column of a highly viscous liquid. The curve in the graph shown, which represents the speed of the ball $\left(v\right)$ as a function of time $\left(t\right)$ is:

Answer 1

As time passes viscous drag acting on ball increases and finally a stage comes, when its speed become constant (called terminal speed).

Hence, option $\left(D\right)$ is the correct answer.