Mercury is filled in a tube of radius $2 \,cm$ up to a height of $30 \,cm$. The force exerted by mercury on the bottom of the tube is . . . . . . $N$.
(Given: atmospheric pressure $P_0 = 10^5 \,N/m^2$,density of mercury $\rho = 1.36 \times 10^4 \,kg/m^3$,$g = 10 \,m/s^2$,$\pi = \frac{22}{7}$)

Water is filled to a height $H$ behind a dam of width $w$. The resultant force on the dam is ..............

$A$ large vessel of height $H$ is filled with a liquid of density $\rho$ up to the brim. $A$ small hole of radius $r$ is made at the side vertical face,close to the base. The horizontal force required to stop the gushing of liquid is ...........

$A$ jet of water having velocity $v = 10 \ m/s$ and stream cross-section $A = 2 \ cm^2$ hits a flat plate perpendicularly,with the water splashing out parallel to the plate. The plate experiences a force of ....... $N$.

Water is flowing at a speed of $1.5\, ms^{-1}$ through a horizontal tube of cross-sectional area $10^{-2}\, m^2$ and you are trying to stop the flow by your palm. Assuming that the water stops immediately after hitting the palm,the minimum force that you must exert should be ......... $N$ (density of water $= 10^3\, kgm^{-3}$)

$A$ tube of length $L$ is filled completely with an incompressible liquid of mass $M$ and closed at both the ends. The tube is then rotated in a horizontal plane about one of its ends with a uniform angular velocity $\omega$. The force exerted by the liquid at the other end is