Pressure head in Bernoulli's equation is

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

Is Bernoulli's equation unsteady? Explain.

Water is filled in a cylindrical container to a height of $3 \ m$. The ratio of the cross-sectional area of the orifice and the beaker is $0.1$. The square of the speed of the liquid coming out from the orifice is ....... $m^2/s^2$ $(g = 10 \ m/s^2)$.

In a horizontal tube,the water pressure changes by $1500 \text{ N m}^{-2}$ between points $A$ and $B$ as shown in the figure below. The cross-sectional areas at $A$ and $B$ of the tube are $40 \text{ cm}^2$ and $20 \text{ cm}^2$,respectively. Find the rate of flow of water through the tube.

Water containing air bubbles flows without turbulence through a horizontal pipe which has a region of narrow cross-section. In this region,the bubbles