A cube of external dimension $10\ cm$ has an inner cubical portion of side $5\ cm$ whose density is twice that of the outer portion. If this cube is just floating in a liquid of density $2\ g/cm^3$, find the density of the inner portion
$\frac{8}{9}\ gm/cc$
$\frac{16}{9}\ gm/cc$
$\frac{32}{9}\ gm/cc$
$\frac{5}{4}\ gm/cc$
Two bodies are in equilibrium when suspended in water from the arms of a balance. The mass of one body is $36 g $ and its density is $9 g / cm^3$. If the mass of the other is $48 g$, its density in $g / cm^3$ is
A stone is projected vertically up from the bottom of a water tank. Assuming no water resistance it will go up and come down in same time but if water drag is present then the time it takes to go up, $t_{up}$ and the time it takes to come down, $t_{down}$ are related as
A jar is filled with two non-mixing liquids $1$ and $2$ having densities $\rho_1$ and, $\rho_2$ respectively. A solid ball, made of a material of density $\rho_3$ , is dropped in the jar. It comes to equilibrium in the position shown in the figure.Which of the following is true for $\rho_1 , \rho_2$ and $\rho_3$?
A dumbbell is placed in water of density $\rho$ . It is observed that by attaching a mass $m$ to the rod, the dumbbell floats with the rod horizontal on the surface of water and each sphere exactly half submerged as shown in the figure. The volume of the mass $m$ is negligible. The value of length $l$ is
A tall tank filled with water has an irregular shape as shown. The wall $C D$ makes an angle of $45^{\circ}$ with the horizontal, the wall $A B$ is normal to the base $B C$. The lengths $A B$ and $C D$ 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 $A B$, base $B C$ and the wall $C D$ respectively. Density of water is $\rho$ and $g$ is acceleration due to gravity. Then, approximately