# Tag Info

## New answers tagged density

3

NaCl melts at around 800°C. Molten NaCl has a density of about $1.556 \frac{g}{cm^3}$[1], at room temperature (solid) it has one of $2.71\frac{g}{cm^3}$ [2]. Sadly I could not find a value for the density at barely underneath melting point but I strongly assume that the density is a strictly monotonously falling function of temperature. Therefore solid NaCl ...

3

This is really a footnote to Carl's answer: As Carl explains, in Mathematics we approach the zero volume/infinite density as a limit and this is a perfectly well defined process. However in Physics we generally don't believe that infinite quantities exist and the occurrence of an infinity is usually a sign that our theory needs modification. In the case of ...

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You need to read up a bit about calculus. This is a case not only of using an idealized situation (cf. the ancient jokes about assuming a spherical cow with a uniform distribution of milk), but, as with delta functions, understanding how a function behaves in the limit, rather than its actual value at that limit. I still recall my first introduction: take ...

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"how does it distinguish case a and b?" Well,let's first clear our conceptions about the archimedes' principle. Then I think you will get your answer for yourself. Archimedes' principle states that, a body immersed in a fluid is buoyed up by a force equal to the weight of the displaced fluid. Focus on this."... a force equal to the weight of the displaced ...

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This will help for sure. http://www.google.com.bd/url?sa=t&rct=j&q=&esrc=s&source=web&cd=4&ved=0CEoQFjAD&url=http%3A%2F%2Fwww.eps.org%2Fresource%2Fcollection%2F016775D4-8888-474D-887F-3E33AEA5E6D0%2FEPSPED_MUSE_2liq.pdf&ei=G5GcUrC4JcLP0QWkjoHgCw&usg=AFQjCNGnjlnYuxkwrUdtqz2f2fgCOyc2Bw&sig2=MELk-Snu28cjA4ezIgHpIg You ...

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You do no say what information you know and do not know. For example if the cube sinks and $h_1$ is big enough, it is possible that $s_2=0$. But if you know $s_1$ and $s_2$ then it is easy. The volume of liquid displaced is $(s_1+s_2)n^2$ so the extra height (ignoring overflows) is $\dfrac{(s_1+s_2)n^2}{\pi R^2 }.$ So the final overall height of the ...

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It's because the densities of the atoms changes. The density of an atom is a somewhat vague concept because an atom doesn't have a sharply defined outer surface. nevertheless you can define a size based on the average lengths of bonds formed by atoms, and if you do this you find the size of atoms decreases along a row in the periodic table even though the ...

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It is due to the molecular structure of the respective liquid. The density depends on chemical composition (are there light atoms or heavy atoms?) and the distances between the atoms (are they closer to each other or more separated?). Liquid hydrogen is very light, because hydrogen has only 1 proton in the nucleus. Liquid iron is heavy, because iron atom has ...

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The confusion arises because there are two kinds of classical limits, depending of the system under study. Let's start with fermions, which distribution is $n_F(\epsilon)=\frac{1}{e^{(\epsilon-\mu)/T}+1}$. The first classical limit (corresponding to the case mentioned in the question) is $T\gg \epsilon-\mu$. This corresponds to the case where the ...

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The introductory paragraph you quote with horror says temperature ''high enough'' to avoid quantum effects. (It did not say anything like ''arbitrarily large''.) If the temperature is too low, things like Bose--Einstein condensation can occur, which invalidate Maxwell--Boltzmann statistics. The temperature should be high enough so that it is unlikely to ...

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I think you're asking if there is some special cutoff density after which spacetime "collapses" and forms a black hole. If this is your question then the answer is no, there is no specific cutoff. Density unites are $\frac{\mathrm{mass}}{\mathrm{volume}}$ but the size of black holes is dependent on the mass and the size is not proportional to the volume ...

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