Difference between Floating and sinking of substance
Floating of substance
1) The relative density of object with respect to water is defined as the ratio density of substance to the density of water.
If ρs =density of substance, ρw =density of water then the relative density (σ) of substance
3) When the value of is smaller than less than 1, the object floats on the water.
4) For eg. Density of wood is 0.5 kg/m3 and density of water is 1 kg/m3, then the relative density of wood with respect to water is σ = 0.5/1 = 0.5 . Hence wood will be floating on the surface of water.
5) In other words if density of substance is less than density of water, it will float on the surface of water.
6) Eg. Density of oil, kerosene, plane is less than that of water, hence they all floats on water.
Sinking of substance
1) The relative density of object with respect to water is defined as the ratio density of substance to the density of water.
2) If ρs = density of substance, ρw = density of water then the relative density (σ) of substance
3) When the value of σ is greater than less than 1, the object sinks in the water.
4) For eg. Density of stone is about 1.65 kg/m3 and density of water is 1 kg/m3, then the relative density of stone with respect to water is σ= 1.62/1=1.62 . Hence stone will be sink into water.
5) In other words if density of substance is greater than density of water, it will sink in the surface of water.
6) Density of metals, stone is greater than that of water, hence they all sinks in water.