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

Why is it dangerous to stand on the edge of a platform near the tracks when a train is passing at high speed? Explain.

The instrument fitted in the carburetor of an automobile to provide the correct mixture of air and fuel necessary for combustion works on which of the following principles?

What is a venturi-meter? Explain its construction and working.

$A$ steady flow of a liquid of density $\rho$ is shown in the figure. At point $1$,the area of cross-section is $2A$ and the speed of flow of liquid is $\sqrt{2} \ m \ s^{-1}$. At point $2$,the area of cross-section is $A$. Between the points $1$ and $2$,the pressure difference is $100 \ N \ m^{-2}$ and the height difference is $10 \ cm$. The value of $\rho$ is (Acceleration due to gravity $= 10 \ m \ s^{-2}$) (in $kg \ m^{-3}$)

Can Bernoulli's equation be used to describe the flow of water through a rapid in a river? Explain.