The volume of $50\, g$ of a substance is $20\, cm^3$. If the density of water is $1\, g\, cm^{-3}$,will the substance float or sink?

An object is placed one by one in three liquids having different densities. The object floats with $\frac{1}{9}$, $\frac{2}{11}$, and $\frac{3}{7}$ parts of its volume outside the liquid surface in liquids of densities $d_1$, $d_2$, and $d_3$ respectively. Which of the following statements is correct?

The volume of a $500\, g$ sealed packet is $350\, cm^3$. Will the packet float or sink in water if the density of water is $1\, g\, cm^{-3}$? What will be the mass of the water displaced by this packet?

Why does a block of plastic released under water come up to the surface of water?

In what direction does the buoyant force on an object immersed in a liquid act?

Why does an object float or sink when placed on the surface of water?