A small spherical solid ball is dropped in a viscous liquid. Its journey in the liquid is best  described in the figure drawn by:-

As the temperature of water increases, its viscosity

Which of the following is not the property of an ideal fluid?

A spherical solid ball of volume $V$ is made of a material of density $\rho_1$ . It is falling through a liquid of density $\rho_2 (\rho_2 < \rho_1 )$. Assume that the liquid applies a viscous force on the ball that is proportional to the square of its speed $v$, i.e., $F_{viscous}= -kv^2 (k >0 )$,The terminal speed of the ball is 

Velocity of water in a river is