An $ L-$ shaped glass tube is just immersed in flowing water such that its opening is pointing against flowing water. If the speed of water current is $v$, then
The water in the tube rises to height $\frac{{{v^2}}}{{2g}}$
The water in the tube rises to height $\frac{g}{{2{v^2}}}$
The water in the tube does not rise at all
None of these
The lift of an air plane is based on
Water is flowing through a horizontal tube according to the figure. Its diameter at two points are $0.3\,m$ and $0.1\,m$ respectively. Pressure difference between these two points is equal to $0.8\,m$ of water column. Find rate of flow of water in the tube ..... $ltr/s$
A fully loaded boeing aircraft has a mass of $5.4 \times 10^5\,kg$. Its total wing area is $500\,m ^2$. It is in level flight with a speed of $1080\,km / h$. If the density of air $\rho$ is $1.2\,kg\,m ^{-3}$, the fractional increase in the speed of the air on the upper surface of the wing relative to the lower surface in percentage will be $\left( g =10\,m / s ^2\right)$
A long cylindrical vessel is half filled with a liquid. When the vessel is rotated about its own vertical axis, the liquid rises up near the wall. If the radius of vessel is $5\,cm$ and its rotational speed is $2$ rotations per second, then the difference in the heights between the centre and the sides, in $cm,$ will be
The reading of pressure metre attached with a closed pipe is $4.5 \times 10^4 \mathrm{~N} / \mathrm{m}^2$. On opening the valve, water starts flowing and the reading of pressure metre falls to $2.0 \times 10^4 \mathrm{~N} / \mathrm{m}^2$. The velocity of water is found to be $\sqrt{\mathrm{V}} \mathrm{m} / \mathrm{s}$. The value of $\mathrm{V}$ is__________