their density is less than that of water
things that have higher density than water will sink as a needle but a hip doesnot.
The densities are equivalent.
Water density depends on the temperature. See this table for density.
no. the density of an object is alone no matter how much you have it is still the same if i have a glass of water its density is 1 if i have an ocean of water its density is 1
Salt Water Density: 1.027 g/mL Fresh Water Density: 1 g/mL
Different oils have different densities; usually a bit less than the density of water.
Because of different densities; being density of oil lower than water density, this makes oil float on water
less than water different objects have varying densities
Objects sink or float depending upon their densities. For example wood floats on water because the density of wood is less than that of water, while a piece of iron would sink in water as its density is more than water.
The density of a salt water solution compared against the densities of "pure" water and salt provides an approximate value of the ratio of water to salt in the mixture.
If the second substance if water, then it is specific gravity. Otherwise, it is just relative density.
Oil and water each have densities. Oil is less dense than water, so it floats above it.