A wooden cylinder floats vertically in water with half of its length immersed. The density of wood is

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 spring with block of same mass, then spring constant is equal to ........ $N/m$

Write the only equation for the volume of partially immerged part of body float on the surface of liquid.

The fraction of a floating object of volume ${V_0}$ and density ${d_0}$ above the surface of a liquid of density $d$  will be

$Assertion :$ The buoyant force on a submerged rigid object can be considered to be acting at the centre of mass of the object.
$Reason :$ For a rigid body a force field distributed uniformly through its volume can be considered to be acting at the centre of mass of the body.

An ornament weighs $10\, g$ in air and $6\, g$ in water. Density of material of ornament is $20\,\frac{g}{{cc}}$. The  volume of cavity in ornament is ........ $cc$