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

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

Explain why bullets of gun are cylinder in shape ?

A cylindrical vessel containing a liquid is rotated about its axis so that the liquid rises at its sides as shown in the figure. The radius of vessel is $5\, cm$ and the angular speed of rotation is  $\omega\; rad \,s^{-1}$. The difference in the height, $h($ in $cm )$ of liquid at the centre of vessel and at the side will be

A manometer connected to a closed tap reads $4.5 \times {10^5}$ pascal. When the tap is opened the reading of the manometer falls to $4 \times {10^5}$ pascal. Then the velocity of flow of water is ........  $m{s^{ - 1}}$

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

(density of water $=1000\; \mathrm{kgm}^{-3}$ )