Two cubical blocks identical in dimensions float in water in such a way that $1$ st block floats with half part immersed in water and second block floats with $3 / 4$ of its volume inside the water. The ratio of densities of blocks is ..........

Write the law of floatation and describe its cases.

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

A cube of edge length $10 \,cm$ is just balanced at the interface of two liquids $A$ and $B$ as shown in figure. If $A$ and $B$ has specific gravity $0.6$ and $0.4$ respectively, then mass of cube is ................ $g$

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

$\left( g =980 \,cm / s ^{2}\right)$

A wooden block, with a coin placed on its top, floats in water as shown in fig. the distance $l $ and $h$ are shown there. After some time the coin falls into the water. Then