$A$ piece of copper having an internal cavity weighs $264\, g$ in air and $221\, g$ in water. Find the volume (in $cc$) of the cavity. Density of $Cu = 8.8\, g/cc$.

Two rods $A$ and $B$ of the same length are made of the same material. The ratio of their resistances is $1 : 2$. If the rods are immersed in water,the loss in their weight will be:

$A$ wide-bottomed cylindrical massless plastic container of height $9 \, cm$ contains $40$ identical coins and is floating on water with $3 \, cm$ of its height submerged. If we start placing additional identical coins on its lid,it is observed that after $N$ coins are added,the equilibrium changes from stable to unstable. Equilibrium in floating is stable if the geometric centre of the submerged portion is above the centre of mass of the object. The value of $N$ is closest to:

$A$ glass flask weighing $390 \ g$,having an internal volume of $500 \ cm^3$,just floats when half of it is filled with water. The specific gravity of the glass is:

Determine the equation for the volume of the partially immersed part of a body floating in a fluid.

$A$ wooden cube of side $10 \ cm$ floats at the interface between water and oil with its lower surface $3 \ cm$ below the interface. If the density of oil is $0.9 \ g \ cm^{-3}$, the mass of the wooden cube is (in $g$)