Water (of density $\varrho$) flows steadily through a horizontal pipe of variable cross-section. If the pressure of water is $P$ at a point where the flow speed is $V$,then the pressure at another point where the flow speed becomes $3V$ is:

Determine the pressure difference in a tube of non-uniform cross-sectional area as shown in the figure. $\Delta P = ?$ (in $Pa$)
$d_{1} = 5 \, cm, V_{1} = 4 \, m/s, d_{2} = 2 \, cm, V_{2} = ?$
Assume the fluid is water with density $\rho = 1000 \, kg/m^{3}$.

$A$ horizontal pipeline carries water in a stream-line flow. At a point along the pipe, where the cross-sectional area is $10 \,cm^2$, the velocity of water is $1 \,m/s$ and the pressure is $2000 \,Pa$. The pressure of water at another point where the cross-sectional area is $5 \,cm^2$ is (Given: density of water $\rho = 1000 \,kg/m^3$) (in $\,Pa$)

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 $1.3 \; kg m^{-3}$.

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

$A$ venturimeter has a pipe diameter of $4 \,cm$ and a throat diameter of $2 \,cm$. The velocity of water in the pipe section is $10 \,m/s$. The pressure drop between the pipe section and the throat section is (use density of water $= 1000 \,kg/m^3$):