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 $(\rho _{air} = 1.2\,kg/m^3)$
$4.8 \times 10^5\,N,$ upwards
$2.4 \times 10^5\,N,$ upwards
$2.4 \times 10^5\,N,$ downwards
$4.8 \times 10^5\,N,$ downwards
If the terminal speed of a sphere of gold (density $\ =\ 19.5 × 10^3\ kg/m^3$ ) is $0.2\ m/s$ in a viscous liquid (density $\ =\ 1.5 × 10^3\ kg/m^3$ ), find the terminal speed of a sphere of silver (density $\ =\ 10.5 × 10^3\ kg/m^3$ ) of the same size in the same liquid ....... $m/s$
For a constant hydraulic stress on an object, the fractional change in the object’s volume $(\Delta V/V)$ and its bulk modulus $(B)$ are related as
A solid cylinder of mass $m$ and volume $v$ is suspended from ceiling by a spring of spring constant $k$ . It has cross-section area $A$ . It is submerged in a liquid of density $\rho $ upto half its length. If a small block of mass $M_o$ is kept at the centre of the top, the amplitude of small oscillation will be
A wooden block with a coin placed on its top floats in water as shown in figure. $l$ and $h$ are as shown. After some time the coin falls into the water then
A cubical block is floating in a liquid with half of its volume immersed in the liquid. When the whole system accelerates upwards with a net acceleration of $g/3$ The fraction of volume immersed in the liquid will be