$A$ cylindrical block of wood of base area $30 \, cm^2$ floats in a liquid of density $900 \, kg/m^3$. The block is depressed lightly and then released. The time period of the resulting oscillations of the block is equal to that of a spring with a block of the same mass. The spring constant is equal to ........ $N/m$.

When an air bubble rises in water,does its potential energy increase or decrease?

An object weighs $m_1$ in a liquid of density $d_1$ and $m_2$ in a liquid of density $d_2$. The density $d$ of the object is

$A$ uniform rod of density $\rho$ is placed in a wide tank containing a liquid of density $\rho_0$ $(\rho_0 > \rho)$. The depth of the liquid in the tank is half the length of the rod. The rod is in equilibrium,with its lower end resting on the bottom of the tank. In this position,the rod makes an angle $\theta$ with the horizontal.

Two bodies having volumes $V$ and $2V$ are suspended from the two arms of a common balance and they are found to balance each other. If the larger body is immersed in oil (density $d_1 = 0.9 \ gm/cm^3$) and the smaller body is immersed in an unknown liquid,the balance remains in equilibrium. The density of the unknown liquid is given by ......... $gm/cm^3$.

$A$ man is carrying a block of a certain substance (of density $1000 \,kg/m^3$) weighing $1 \,kg$ in his left hand and a bucket filled with water and weighing $10 \,kg$ in his right hand. He drops the block into the bucket. How much load does he carry in his right hand now (in $,kg$)?