Consider the wall of a dam to be straight with height $H$ and length $L$. It holds a lake of water of height $h (h < H)$ on one side. Let the density of water be $\rho_{ w }$. Denote the torque about the axis along the bottom length of the wall by $\tau_1$. Denote also a similar torque due to the water up to height $h / 2$ and wall length $L / 2$ by $\tau_2$. Then $\tau_1 / \tau_2$ (ignore atmospheric pressure) is
$2$
$4$
$8$
$16$
A large vessel of height $H$, is filled with a liquid of density $\rho$, upto the brim. A small hole of radius $r$ is made at the side vertical face, close to the base. The horizontal force is required to stop the gushing of liquid is ...........
A liquid is kept in a cylindrical vessel which rotated along its axis. The liquid rises at the sides. If the radius of the vessel is $0.05\,m$ and the speed of rotation is $2\,rev/s$ , The difference in the height of the liquid at the centre of the vessel and its sides will be .............. $\mathrm{cm}$ $(\pi ^2 = 10)$
A bucket contains water filled upto a height $=$ $15 cm$. The bucket is tied to a rope which is passed over a frictionless light pulley and the other end of the rope is tied to a weight of mass which is half of that of the (bucket $+$ water). The water pressure above atmosphere pressure at the bottom is ....... $kPa$
A tank $5\, m$ high is half-filled with water and then is filled to the top with oil of density $0.85\, g/cm^3$. The pressure at the bottom of the tank, due to these liquids is ....... $g\, dyne/cm^2$
Water is filled up to a height $h$ in a beaker of radius $R$ as shown in the figure. The density of water is $\rho$, the surface tension of water is $T$ and the atmospheric pressure is $P_0$. Consider a vertical section $A B C D$ of the water column through a diameter of the beaker. The force on water on one side of this section by water on the other side of this section has magnitude