An aeroplane of mass $3 \times 10^4\,kg$ and total wing area of $120\,m^2$ is in a level flight at some height. The difference in pressure between the upper and lower surfaces of its wings in kilopascals is........... $kPa$ $(g=10\,m/s^2)$

Which fundamental law forms the basis of Bernoulli's equation?

In a test experiment on a model aeroplane in a wind tunnel,the flow speeds on the upper and lower surfaces of the wing are $70 \; m s^{-1}$ and $63 \; m s^{-1}$ respectively. What is the lift on the wing if its area is $2.5 \; m^{2}$? Take the density of air to be $1.3 \; kg m^{-3}$.

Consider a water tank as shown in the figure. Its cross-sectional area is $0.4\, m^{2}$. The tank has an opening $B$ near the bottom whose cross-sectional area is $1\, cm^{2}$. $A$ load of $24\, kg$ is applied on the water at the top. When the height of the water level is $40\, cm$ above the bottom,the velocity of water coming out of the opening $B$ is $v\, ms^{-1}$. The value of $v$,to the nearest integer,is ......$m/s$. [Take value of $g$ to be $10\, ms^{-2}$]

Water is flowing through a horizontal tube having cross-sectional areas of its two ends as $A$ and $A'$ such that the ratio $A/A'$ is $5$. If the pressure difference of water between the two ends is $3 \times 10^5 \, N \, m^{-2}$,the velocity of water with which it enters the tube will be ......... $m \, s^{-1}$ (neglect gravity effects).

The venturi-meter works on: