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 $(\rho _{air} = 1.2 \,\,kg/m^3)$
$4.8 \times 10^5 N$, downwards
$4.8 \times 10^5 N$, upwards
$2.4 \times 10^5 N$, upwards
$2.4 \times 10^5 N,$ downwards
An application of Bernoulli's equation for fluid flow is found in
Figures below show water flowing through a horizontal pipe from left to right. Note that the pipe in the middle is narrower. Choose the most appropriate depiction of water levels in the vertical pipes.
What is a venturi-meter ? Explain its construction and working.
A steel wire is suspended vertically from a rigid support. When loaded with a weight in air, it extends by $l_a$ and when the weight is immersed completely in water, the extension is reduced to $l_w$. Then the relative density of material of the weight is
At what speed, the velocity head of water is equal to pressure head of $40 \,cm$ of mercury is ........ $m / s$