A tank with a small hole at the bottom has been filled with water and kerosene (specific gravity $0.8$). The height of water is $3\,m$ and that of kerosene $2\,m$. When the hole is opened the velocity of fluid coming out from it is nearly ........ $ms^{-1}$ .(take $g\, = 10\, m s^{-2}$ and density of water $= 10^3\, kg\, m^{-3}$)

The pressure of water in a water pipe when tap is opened and closed is respectively $3 \times 10^5\,N/m^2$ and $3.5 \times 10^5\,N/m^2$ . With open tap, the velocity of water flowing is ........... $m/s$

Explain why roof of building flyout during stormy wind.

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

A plane is in level flight at constant speed and each of its two wings has an area of $25 \;m ^{2}$ If the speed of the air is $180 \;km / h$ over the lower wing and $234\; km / h$ over the upper wing surface, determine the plane's mass in $kg$. (Take air density to be $1\; kg m ^{-3}$ ).

Write limitations of Bernoulli’s theorem.