0
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1answer
39 views

Finding a 1-Dimensional Mass Distribution

Past Discussion There have been a lot of questions and discussions regarding determining the mass distribution of various bodies through non-destructive purposes. Here are a few: Determination of ...
0
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1answer
48 views

Density as a function of Temperature?

I know that volume = mass/density....and density is the function of temperature. Is there any standard equation that describes density as a function of temperature? The system I am interested in is ...
0
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2answers
108 views

Point masses and infinite densities

Point masses are masses who don't have volume. It is said that they are infinitly dense, but I though division by zero is undefined hence you can't define the density for a point mass because ...
1
vote
1answer
94 views

Singularity in a black hole [duplicate]

This might be a naive question, but how can an object such as a black hole singularity have infinite density but finite mass? (For example, we can approximate the mass of a black hole based on ...
1
vote
2answers
110 views

Possibility of determining the mass of the water without a scale?

Possibility of determining the mass of the water by knowing water volume, water temperature and atmospheric pressure. I want to know if I can determine the mass of $V=0.01\,m^3$ of water in ...
3
votes
2answers
299 views

Determination of mass density distribution of an object

This is a follow-up to a previous question How can you weigh your own head in an accurate way?. My purpose is not to restart the flurry of more or less humorous jokes (which are not such a bad thing ...
1
vote
1answer
226 views

What happens when I increase the density of a stellar object so that its mass surpasses the Schwarzschild limit?

We know that every object that has mass, also has a Schwarzschild radius $r_s$: $$r_s = \frac{2Gm}{c^2}$$ With $G$ being Newton's gravitational constant, $m$ the mass of the object and $c$ the speed ...
5
votes
3answers
337 views

Is it possible to have a singularity with zero mass?

A singularity, by the definition I know, is a point in space with infinite of a property such as density. Density is Mass/Volume. Since the volume of a singularity is 0, then the density will thus ...
-2
votes
1answer
193 views

Suppose a hollow metal sphere filled with helium is dropped in a body of water

What are the conditions that would cause said sphere to sink or float? What if the sphere was full of ice instead?
4
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1answer
674 views

Planetary Gravity and its effects

This is my first question on the Physics portion of Stack Exchange. I was hoping to get some light on the topic of gravity. I don't have much background knowledge of physics so I might as well start ...
1
vote
1answer
226 views

What is the definition of density as a function?

(Before I start, I don't know which tag is suitable for this post. Please retag my post if it bothers you.) Let's say there is a string on $[0,1]$ with a mass given by $m(x)$. ($m(x)$ means the mass ...
0
votes
3answers
202 views

Center Of Mass Troubles

I understand the concept of Center Of Mass(com), but I am having a difficult time interpreting the equation of the simplified case of one-dimension. The book I am reading defines the position of the ...
9
votes
4answers
3k views

Density of a proton

I was doing some exercises the other day, when I came across this question in my book: A proton weighs about 1.66 x 10-24 g and has a diameter of about 10-15 m. What is its density in g/cm3? ...
12
votes
4answers
2k views

Why does a black hole have a finite mass?

I mean besides the obvious "it has to have finite mass or it would suck up the universe." A singularity is a dimensionless point in space with infinite density, if I'm not mistaken. If something is ...