A ball of relative density $0.8$ falls into water from a height of $2$ $m$. The depth to which the ball will sink is ........ $ m$ (neglect viscous forces) :

A solid sphere of specific gravity $27$ has a concentric spherical cavity and it just sinks in water. The ratio of cavity radius to that of outer radius of sphere is

A body having volume $V$ and density $\rho$ is attached to the bottom of a container as shown. Density of the liquid is $d( > \rho )$. Container has a constant upward acceleration $a.$ Tension in the string is

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 ................ $g$

Water coming out of a horizontal tube at a speed ? strikes normally a vertically wall close to the mouth of the tube and falls down vertically after impact. When the speed of water is increased to $2v$ .

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