JEE Main 2021 — Mechanical Properties of Fluids Question with Solution

Consider a water tank as shown in the figure. It's cross-sectional area is $0.4{ \mathrm{m}}^2$. The tank has an opening $B$ near the bottom whose cross-section area is $1{ \mathrm{cm}}^2$. A load of $24 \mathrm{kg}$ is applied on the water at the top when the height of the water level is $40 \mathrm{cm}$ above the bottom, the velocity of water coming out the opening $B$ is $\mathrm{v} \mathrm{m} {\mathrm{s}}^{-1}$. The value of $v$, to the nearest integer, is ___ .[Take the value of $g$ to be $10{ \mathrm{m} \mathrm{s}}^{-2}$]