The area of cross-section of the wider tube shown in the figure is $800 \ cm^2$. If a mass of $12 \ kg$ is placed on the massless piston,the difference in heights $h$ in the level of water in the two tubes is ........ $cm$.

$A$ tall tank filled with water has an irregular shape as shown. The wall $CD$ makes an angle of $45^{\circ}$ with the horizontal,the wall $AB$ is normal to the base $BC$. The lengths $AB$ and $CD$ are much smaller than the height $h$ of water (figure not to scale). Let $p_1, p_2$ and $p_3$ be the pressures exerted by the water on the wall $AB$,base $BC$ and the wall $CD$ respectively. Density of water is $\rho$ and $g$ is acceleration due to gravity. Then,approximately

$A$ hydraulic automobile lift is designed to lift cars with a maximum mass of $3000 \, kg$. The area of cross-section of the piston carrying the load is $425 \, cm^{2}$. What is the maximum pressure the smaller piston would have to bear?

Two syringes of different cross-sections (without needles) filled with water are connected with a tightly fitted rubber tube filled with water. Diameters of the smaller piston and larger piston are $1.0 \; cm$ and $3.0 \; cm$ respectively.
$(a)$ Find the force exerted on the larger piston when a force of $10 \; N$ is applied to the smaller piston.
$(b)$ If the smaller piston is pushed in through $6.0 \; cm$,how much does the larger piston move out?

In a hydraulic jack as shown,the mass of the car is $W = 800 \, kg$,$A_1 = 10 \, cm^2$,and $A_2 = 10 \, m^2$. The minimum force $F$ required to lift the car is ........... $N$.

$A$ hydraulic lift is shown in the figure. The radii of the movable pistons $P_1$ and $P_2$ are $2 \,m$ and $8 \,m$ respectively. If a body of mass $2 \,kg$ is placed on piston $P_1$, then the force on piston $P_2$ is (Ignore atmospheric pressure, acceleration due to gravity $= 10 \,ms^{-2}$) (in $\,N$)