$A$ manometer connected to a closed tap reads $4.5 \times 10^5 \text{ Pa}$. When the tap is opened,the reading of the manometer falls to $4 \times 10^5 \text{ Pa}$. The velocity of the flow of water is ........ $m/s$.

$A$ 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 $(g = 10 \, m/s^2)$.

Air of density $1.2 \, kg \, m^{-3}$ is blowing across the horizontal wings of an aeroplane in such a way that its speeds above and below the wings are $150 \, m \, s^{-1}$ and $100 \, m \, s^{-1}$,respectively. The pressure difference between the upper and lower sides of the wings is ........ $N \, m^{-2}$.

Which types of energies are present in the streamline flow of an ideal fluid?

Water flows in a horizontal tube (see figure). The pressure of water changes by $700 \; Nm^{-2}$ between $A$ and $B$ where the area of cross-section are $40 \; cm^{2}$ and $20 \; cm^{2},$ respectively. Find the rate of flow of water through the tube in $cm^{3} / s$. (Density of water $= 1000 \; kgm^{-3}$)

Water is flowing through a horizontal tube as shown in the figure. Its diameters at two points are $0.3\,m$ and $0.1\,m$ respectively. The pressure difference between these two points is equal to $0.8\,m$ of water column. Find the rate of flow of water in the tube in $ltr/s$.