Water flows through a frictionless duct with a cross-section varying as shown in figure. Pressure $p$ at points along the axis is represented by

At what speed, the velocity head of water is equal to pressure head of $40 \,cm$ of mercury is ........ $m / s$

Water flows in a horizontal tube as shown in figure. The pressure of water changes by $600\, N/ m^2$ between $A$ and $B$ where the area of crosssection are $30\, cm^2$ and $15\, cm^2$ respectively. Find the rate of flow of water through the tube.

Write the limitations of Bernoulli’s equation..

In a test experiment on a model aeroplane in wind tunnel, the flow speeds on the upper and lower surfaces of the wings are $70 \mathrm{~ms}^{-1}$ and $65 \mathrm{~ms}^{-1}$ respectively. If the wing area is $2 \mathrm{~m}^2$ the lift of the wing is__________ $\mathrm{N}$.

(Given density of air $=1.2 \mathrm{~kg} \mathrm{~m}^{-3}$ )

Prove Bernoulli’s Principle.