The venturi-meter works on:

The velocity of kerosene in a horizontal pipe is $5 \ m/s$. What is the velocity head in $m$? (Take $g = 10 \ m/s^2$)

Water from a tap emerges vertically downwards with an initial velocity of $4 \,m/s$. The cross-sectional area of the tap is $A$. The flow is steady and the pressure is constant throughout the stream of water. The distance $h$ vertically below the tap,where the cross-sectional area of the stream becomes $\frac{2}{3} A$,is (take $g = 10 \,m/s^2$): (in $\,m$)

$A$ liquid enters at point $A_{1}$ with a speed of $3.5 \ m/s$ and leaves at point $A_{2}$. Find the height attained by the liquid above point $A_{2}$ (in $cm$). (in $.25$)

What type of fluid can be applied in Bernoulli's equation?