$A$ wooden block floats in a liquid with $40\%$ of its volume inside the liquid. When the vessel containing the liquid starts rising upwards with an acceleration $a = g/2$, the percentage of volume inside the liquid is ......... $\%$

In which case does the potential energy decrease?

An air bubble of radius $1\,cm$ in water has an upward acceleration of $9.8\,cm\,s^{-2}$. The density of water is $1\,g\,cm^{-3}$ and water offers negligible drag force on the bubble. The mass of the bubble is $.......g$.
$(g = 980\,cm\,s^{-2})$

$A$ vessel filled with water is kept on a weighing pan and the scale is adjusted to zero. $A$ block of mass $M$ and density $\rho$ is suspended by a massless spring of spring constant $k$. This block is submerged into the water in the vessel. What is the reading of the scale?

$A$ body floats in water with $40 \%$ of its volume outside water. When the same body floats in an oil, $60 \%$ of its volume remains outside oil. The relative density of oil is

Two non-mixing liquids of densities $\rho$ and $n\rho$ $(n > 1)$ are put in a container. The height of each liquid is $h$. $A$ solid cylinder of length $L$ and density $d$ is placed in this container. The cylinder floats with its axis vertical and a length $pL$ $(p < 1)$ submerged in the denser liquid. The density $d$ is equal to: