Fluids Questions

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 $F_{\text{viscous}}=-k{v}^2$. The terminal speed of the ball is:

A capillary tube (A) is dipped in water. Another identical tube (B) is dipped in soap water solution. Which of the following shows the relative nature of the liquid columns?

A ball is made of a material of density $\rho$ where ${\rho }_{oil}<\rho <{\rho }_{water}$ with ${\rho }_{oil}$ and ${\rho }_{water}$ representing the densities of oil and water, respectively. The oil and water are immiscible. If the above ball is in equilibrium in a mixture of this oil and water, which of the following describes its equilibrium position?

A thin liquid film formed between a U-shaped wire and a light slider supports a weight of $1.5\times 10^{-2}\text{N}$. The length of the slider is $30\text{cm}$ and its weight is negligible. The surface tension of the liquid film is: