# density's questions - English 1answer

457 density questions.

### Density and refractive index of Water/sugar solution

I can't find a correlation or equation for refractive index of water and sugar solution of known density. Do you know where to find it?

### Diamond ring around black hole

1 answers, 64 views black-holes speed-of-light density
I know that light takes longer to travel in a denser material, like diamond and I know that black holes also attract light. I was wandering what would happen if you would make a ring out of diamond, ...

### Measuring local properties in a suspension

0 answers, 7 views fluid-dynamics acoustics density
Considering a fluid with a certain known concentration of particles (eg: 40% per volume RBCs in blood plasma), how do I measure analytically the speed of sound in the medium and its density? i.e. ...

### Does the density of water affect the speed of sea waves?

2 answers, 26 views waves water speed density
In the case of light waves, the denser the matter, the more slowly they propagate. Do the water waves behave identically?

### -1 Neutron star matter density [duplicate]

1 answers, 58 views density states-of-matter
Edit: Replaced black hole with neutron star, thanks to safesphere for his comment. We're told that tiny volumes of matter have huge mass in a neutron star. For the sake of argument, if you had a 1cm ...

### 2 Density solver for ideal mixture of real gases

1 answers, 273 views thermodynamics pressure density
I am referring the paper on GERG-2008 equation of state. I am interested in calculating the properties of ideal mixtures of real gases. The GERG-2008 EOS is in Helmholtz free energy and hence the ...

### 5 What atomic forces are acting to resist me pushing an air filled bottle underwater?

Yes air is less dense than water but how does the bottle know to rise or indeed to move? It's not electromagnetism I think. Does this have a relation to gravitational forces? Is it to do with the ...

### Finding density using bulk stress equation

Basically, I'm using the equation $\frac{F}{A} = -B\times \frac{\bigtriangleup V}{V_o}$. Originally I had to find the change in volume given an initial volume (B and pressure ($\frac{F}{A}$) were ...

### 9 Can you make a metal denser by melting it and make it cool down under high pressure?

The answer is probably no. But can you make a metal denser by melting it and make it cool down under high pressure? Or would it just crack under internal stress when it returns to a solid? I'm going ...

### 21 The Density of Clouds

Clouds are made up of tiny water or ice droplets, depending on temperature. This implies that cloud density is greater than that of dry air. Why don't clouds sink through their surrounding atmosphere ...

### 3 Hot air balloon - mass

2 answers, 664 views pressure density
Short background I'm aware that a hot air balloon rises up because of the less density than air. But I'm not sure about how that lower density is reached, and how it can be sustained over time. At ...

### How do I find out the net thrust produced by a propeller?

I am trying to find out the thrust that a propeller produces. Since a propeller can have various different types of inclination for it's blades as well as several parameters such as number of blades, ...

### How does an aspirator pump work?

The below picture is of a aspirator pump. If we press the bulb at A the air in it with density $\sigma$ will flow out with velocity $V$. This would cause lower pressure at B and hence the liquid with ...

### Effect of aeration on Celerity

0 answers, 35 views waves density oceanography
Suppose a ocean wave encountered a section of ocean which had a higher level of aeration from gas such as methane escaping from the seafloor. Due to the aerated sections apparent lower density would ...

### How to know wind speed, given the force

I'm doing a game that is set in a desert and there are sand storms that occur periodically. What I've done is very basic and far from realistic, which is ...

### 30 Why singularity in a black hole, and not just “very dense”?

Why does there have to be a singularity in a black hole, and not just a very dense lump of matter of finite size? If there's any such thing as granularity of space, couldn't the "singularity" be just ...

### How Can Somehing With Mass Have Zero Volume? [duplicate]

I am very under qualified when it comes to physics. So, please correct me if I asked a question that “can’t be asked”. With that being said, I ABSOLUTELY love astrophysics. Which is obviously ...

### What is meant by a uniform body and continuous body in physics? [closed]

Is uniform mass and continuous mass is same as uniform body and continuous body? Examples of uniform, non-uniform, continuous and non-continuous mass/bodies? Please also explain a little bit. while ...

### Newtonian Fluid Waves

Suppose I have a wave tank partially filled with a shear thickening Newtonian fluid (Oobleck), on top of which sits a layer of water (separated by a thin membrane to prevent mixing) If I propagate a ...

### 11 How can super massive black holes have a lower density than water?

6 answers, 10.594 views black-holes density event-horizon
I heard on a podcast recently that the supermassive black holes at the centre of some galaxies could have densities less than water, so in theory, they could float on the substance they were gobbling ...

### Are all black holes singularities identical?

There seems to be a problem between a singularity and the event horizons size. My logic is this if u have two collapsing stars with different masses there horizons will be different in diameter yet ...

### -1 Why does oil float on water?

This might be a silly question but I want to know why oil actually floats on water. I tried to explain it to myself using Archimedes' principle but that didn't help. Archimedes’ principle, ...

### 5 Longitudinal Waves - how velocity varies with density

1 answers, 10.180 views waves velocity density
The formula for finding the velocity of a longitudinal wave, such as a sound wave, is: $$v = \sqrt{\frac{E}{\rho}}$$ Where $v$ represents the velocity, $E$ represents the elasticity of the medium, and ...

### How dense could an Earth-sized planet be before beginning to undergo fusion?

I'm trying to figure out the maximum possible density for an earth-sized planet before it would become an earth-sized star. To try to figure this out, I found a reference star, VB 10, known for being ...

### 4 Metallic hydrogen and gaseous planets

Jupiter has about twice the density of Saturn (1.33 versus 0.69 g/cm^3) because it apparently has a higher mass percentage of rocky core and of metallic hydrogen in its interior. Available density ...

### 3 Liquid density as a function of pressure and temperature, how to model experimental data of $\rho(p,T)$?

I’m going to ask my question, explain the problem, show what I have done, and then re-state my question. (Note, perhaps this is a question better suited for https://stats.stackexchange.com/ or https:...

### 1 Ice floating on water [duplicate]

Why is the hydrogen bond different from other bonds that allows ice to float in water rather tan sink. I don't want the math. I want the reason that bond is different than the rest. Why, not how.