The diagram (figure) shows a venturimeter, through which water is flowing. The speed of water at $X$ is $2\,cm/s.$ The speed of water at $Y$ (taking $g = 1000 \,cm/s^2$ ) is ........ $cm/s$

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

If water is flowing in a pipe with speed $2 \,m / s$ then its kinetic energy per unit volume is ........... $J ^2 m ^3$

At what speed the velocity head of a stream of water be equal to $40 cm $ of $Hg$  ........ $cm/sec$ 

In a test experiment on a model aeroplane in wind tunnel, the flow speeds on the upper and lower surfaces of the wings are $70 \mathrm{~ms}^{-1}$ and $65 \mathrm{~ms}^{-1}$ respectively. If the wing area is $2 \mathrm{~m}^2$ the lift of the wing is__________ $\mathrm{N}$.

(Given density of air $=1.2 \mathrm{~kg} \mathrm{~m}^{-3}$ )

Water flows through a frictionless duct with a cross-section varying as shown in figure. Pressure $p$ at points along the axis is represented by