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 $10{ \mathrm{m} \mathrm{s}}^{-2}$]

The boxes of masses $2 \mathrm{kg}$ and $8 \mathrm{kg}$ are connected by a massless string passing over smooth pulleys. Calculate the time taken by box of mass $8 \mathrm{kg}$ to strike the ground starting from rest.  $\left(\mathrm{g}=10 \mathrm{m} {\mathrm{s}}^{-2}\right)$ 

The resultant of these forces $\overrightarrow{OP},\overrightarrow{OQ},\overrightarrow{OR},\overrightarrow{OS}$ and $\overrightarrow{OT}$ is approximately ______$\mathrm{N}.$
[Take $\sqrt{3}=1.7,\sqrt{2}=1.4$ Given $\hat{\mathrm{i}}$ and $\hat{\mathrm{j}}$ unit vectors along $x, y$ axis]

The coefficient of static friction between two blocks is $0.5$ and the table is smooth. The maximum horizontal force that can be applied to move the blocks together is _______$\mathrm{N}$ (take $\left.g=10{ \mathrm{m} \mathrm{s}}^{-2}\right)$