Too many variances to give a concise answer. There are hundreds of types of wood, each with its own density and strength variables. The object that hits them is also going to be a factor, as an ax is going to be very different then a Baseball bat, which is different then a fireplace Poker. It takes some 250 pounds of force to crush the average human skull, but that depends also on where you are squeezing it.
Wood floats on the water normally. Human bones sink. So human bones are more dense than most woods. Human skull is much more impact resistant than most woods of the same size and shape.
Perhaps you mean "specific gravity". That refers to an object's density, compared to the density of a reference subtance (usually water). For example, if iron has 8 times the density of water, then its specific gravity is said to be 8.
I sugest you look up "steam tables". Since convection currents are caused solely by diferences in density ... yes, it is assumed that tempreture diferences CAUSED the density gradiant - but that is not always true.
Density would be the most noticeable difference between the rock and the model.
Salt water is a lighter density than fresh. The difference depends on the salinity of the water. This differs all over the world in different parts of the oceans and in salt water lakes.
Salinity, or saltiness, affects how readily the water changes temperatures as well as its density. Because of this, currents in the water can arise not only from the difference in temperature, but also from the density difference, which comes from the salinity itself.
mass dose not change on a spaceship
Rock is hundreds to thousands of times denser than any gas under normal conditions.
Its larger density, and weather and stain resistant structure prevents it from splintering, warping, rotting, or splitting. And compared to other woods, it is virtually maintenance free.
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mass / volume = density relative density is that compared to water ( 1g / cm3)
The density of an object that sinks is greater than the density of the liquid in which it sinks.
Well that depends, do you think 0.79 grams is high? Compared to water, which has a density of 1.0 grams.. so does alcohol have a high density compared to water? No. :P
The difference in water density (hot-cold) is very small, compared to the difference in density between water of any temperature, and your body. That is, even hot water is more dense that we are, so we still float.
It is going to need to be divide by the original density and then after you find that out you get your answer.
size does not relate to density
mass / volume = density relative density is that compared to water ( 1g / cm3)
If the gold is of the same purity the density will be the same.