What is Aerofoil ? Explain .
In figure an aerofoil is shown, which is a solid piece shaped to provide an upward dynamic lift when it moves horizontally through air.
The cross section on the wings of an aeroplane looks somewhat like the aerofoil (shown in figure) with streamlines around it.
When the aerofoil moves against the wind, the orientation of the wing relative to flow direction causes the streamlines to crowd together above the wing more then those below it. The flow speed on top is higher than that below it.
This balances the weight of the plane.
A horizontal pipe line carries water in a streamline flow.At a point along the tube where the cross-sectional area is $10^{-2}$ $m^2$, the water velocity is $2$ $ms^{^{-1}}$ and the pressure is $8000 $ $Pa$. The pressure of water at another point where the cross-sectional area is $0.5$ $\times 10^{-2}$ $m^2$ is ........ $Pa$
A wind with speed $40\,\, m/s$ blows parallel to the roof of a house. The area of the roof is $250\, m^2.$ Assuming that the pressure inside the house is atmospheric pressure, the force exerted by the wind on the roof and the direction of the force will be $(\rho _{air} = 1.2 \,\,kg/m^3)$
A tube is attached as shown in closed vessel containing water. The velocity of water coming out from a small hole is :
An $ L-$ shaped tube with a small orifice is held in a water stream as shown in fig. The upper end of the tube is $ 10.6 cm$ above the surface of water. ....... $cm$ will be the height of the jet of water coming from the orifice ? Velocity of water stream is $2.45 m/s$
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 ........... $m/s$