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2
votes
2answers
52 views

Why do some materials shrink when their temperature increases?

In my vision it would seem quite logical that all materials expand when temperature rises. Because the particles get more energy and travel larger distances when moving. But apparently there are ...
0
votes
1answer
40 views

Understanding the relation between pressure, ideal gas and, volume

I was given the following formula which is used for ideal gasses: $$pV = nRT$$ where: p:pressure V: volume n: number of moles R: gasconstant T: temperature now when speaking about vaporpressure ...
1
vote
0answers
29 views

Volume Operator / volume phase-space-function in thermodynamics

In Thermodynamics, one often encounters the derivation of pressure as the generalised force that belongs to the extensive state-variable of the volume. Postulates: One looks just at a system of many ...
0
votes
2answers
71 views

How to measure the mass of the lower part of a human body?

An Olympic weightlifter asked me this question and it has been bugging me for a couple of days now. Suppose "lower part" is defined as anything below and including the hip. This means that the ...
0
votes
1answer
43 views

Precision of the edge of a cube versus the volume of a cube [closed]

The edge of a cube was measured with 1% precision. How is the precision of the volume of same cube calculated on the basis this measurement? Is it true that precision of the measurement would be 3%?
0
votes
1answer
18 views

Understanding why 2*density of a isolated gas equals half the initial temperature

A vertical cylinder of cross-sectional area 0.050 m2 is fitted with a tight-fitting, frictionless piston of mass 5.00 kg. The cylinder contains 3.00 mol of an ideal gas at 227°C. At what temperature ...
-1
votes
1answer
46 views

how to calculate diameter and length change from volume change for a hollow cylinder?

I have a cylindrical material with a hole going through its center all along the larger dimension (length). I know the dimensions and the volume of the cylinder at temperature T1. Now, if I heat it up ...
0
votes
1answer
31 views

Why divide surface area to volume for strength in living beings? [duplicate]

As the title says, why divide surface area to volume for strength in living beings ? I mean why all surface area ? Shouldn't it be area touching the ground ? Thanks in advance! :)
2
votes
1answer
81 views

Does limiting to infinity violate laws of physics?

It is noteworthy that one cannot simply divide any length more than the Planck-length. If so, one cannot simply divide any volume more than the $(Planck-length)^3$. So if I want to find the limit of ...
0
votes
2answers
133 views

When Sugar Is Added to Water, How Does the Mass Change, and How does That Affect the Water's Density and Boiling Point?

I can't find a good answer anywhere. How does the amount of sugar added change the boiling point, mass, and density of water? Does it affect the mass or the volume? Or both?
0
votes
2answers
30 views

Dimensional equation for measuring logarithm of volume

I have a measure that uses radiation dose (M.U. $Gray$) and $\log(Volume)$. The measure is $[\frac{Dose}{\log(Volume)}]$ that is $[\frac{D}{\log(l^3)}]$ with $D$ as radiation dose (M.U. unit is Gray) ...
1
vote
1answer
66 views

Pressure Calculation - Compressed Air Volume [closed]

I am trying to calculate the change in pressure in a closed pressure vessel that is being compressed. For the sake of simplicity we can consider this to be a syringe with a closed end that is being ...
0
votes
1answer
52 views

why is air pressure in force per area instead of volume?

The basic unit of Pascals, (Pa), is one Newton (N) per meter square (area). Why is this, especially for things like air pressure that deal with three dimensional space? Shouldn't something like air ...
3
votes
3answers
360 views

Problem in understanding the Proof of $PV^{\gamma}$ =constant in thermodynamics

I have looked at the proof of this relation $PV^\gamma = C$; (where $P$ is pressure and $V$ is volume) in quite some places but I am not able to understand the logic behind the third step. In ...
1
vote
0answers
55 views

Is $d^3r$ the same as $dV$, the volume element?

I've seen the term $d^3r$ being used instead of $dV$. Are they exactly the same? Do they have a different connotation?
0
votes
1answer
25 views

Investigating volume of a crater

I determined the shape of the crater to be a spherical cap. According to this website, http://mathforum.org/library/drmath/view/55253.html , its formula is described as $$V_{cap} = \frac{1}{6} \pi h ...
1
vote
5answers
687 views

Is it possible for an object to have mass but zero volume?

Can there exist a particle/object in the universe having mass but no volume? Is it possible that mass can exist without volume and density? We think we know that matter is anything having mass and ...
1
vote
1answer
44 views

What is the atomic composition of the human body, by volume?

According to Wikipedia, the composition (by atomic percent) of the human body is: 62% hydrogen 24% oxygen 12% carbon 1% nitrogen etc. Question: What is our volumetric composition*? *I get this is ...
0
votes
3answers
861 views

Specific heat capacity at constant volume VS constant pressure

For an ideal gas, why is the specific heat capacity at constant volume lower than the specific heat capacity at constant pressure?
0
votes
0answers
22 views

Construct bivariate symmetric (polynomial) Hilbert-Schmidt two-qubit volume functions over the unit square with certain properties

Construct bivariate symmetric polynomials (two-qubit volume functions) f(r,R) = f(R,r) >= 0 over [0,1]^2, with f(1,R) = f(r,1)=0, such that the univariate marginal (integrating over r or R) ...
-2
votes
1answer
110 views

Where is error in this method of finding volume of sphere using integration? [closed]

Where is error in this method of finding volume of sphere using integration?
1
vote
1answer
617 views

How do I keep the temperature constant in a Boyle's Law experiment?

I'm trying to get a head start on our lab experiment next week about Boyle's Law. The set-up is we have an air chamber can immersed in a pot of boiling water (which is kept boiling over an electric ...
0
votes
0answers
19 views

How can I estimate the density of non-ideal vapor mixtures

I am trying to estimate the density of a non-ideal gas mixture and can't seem to find any resources for how to go about this. For some gas pairs like ammonia-water there are empirical correlations ...
2
votes
3answers
213 views

Would a person gain or lose weight after expelling a flatus?

Considering the chemical composition, mass, and pressure range of typical human flatulence, would a person gain or lose weight after passing gas?
0
votes
2answers
190 views

Calculate volume of a crater

Is there an equation I can use to determine the volume of a crater in my 'drop the ball on sand' experiment? I looked at the equations for volume of hemisphere and cone but do not seem to fit the ...
0
votes
1answer
64 views

Question about pistons and how their volume is affected by particles?

I can't find an answer to this anywhere. When pressure is maintained in a piston and an ideal gas is injected into it (again, with no change in pressure as it is injected) the piston is displaced ...
0
votes
0answers
81 views

Is Isochoric compression or expansion possible?

Stirling cycle is made of two isothermal and two isochoric processes. Heat is added isothermally, expansion and compression takes place isochorically, as given by the book. How can a gas be ...
2
votes
2answers
82 views

Why is the introduction of a quantization volume necessary for quantization of the EM field

I have been working through the quantization of the electromagnetic field, and every source I find introduces a quantization volume with periodic boundary conditions in the process, in which we fit ...
1
vote
0answers
33 views

Zero mean curvature and maximal volume

I have a 1+1 asympotically flat spacetime system (spherical symmetry) for which I'm trying to find the hypersurface which maximizes the volume enclosed in a sphere of a given radius $r=R$. **It seems ...
1
vote
1answer
95 views

Minimal phase space volume $h^3$ out of Heisenberg's principle

So the explanation in my text book is this: we have a phase space volume $\Delta x\Delta y\Delta z\Delta p_x\Delta p_y\Delta p_z$. Now they state that Heisenberg's uncertainty principle states $\Delta ...
1
vote
1answer
986 views

How does the bulk modulus of air change with rising pressure?

I can't seem to find the answer to what should be a trivial question: I have a rigid air-tight container of fixed volume and I am pumping air inside. The pressure is increasing (very slowly) from ...
2
votes
1answer
194 views

Relationship of the volume of a plumbing system to pressure

How does the volume of water a plumbing system holds vary with water pressure? I know the ratio would include the modulus of elasticity of the plumbing material, the total surface area of the plumbing ...
1
vote
2answers
69 views

Charles Law inverse for cooling?

Is the inverse of Charles law also true? If I double the volume, the temperature will be halved? In the fire service we ventilate a structure by opening up the ceiling to the attic. If the volume of ...
12
votes
3answers
633 views

What are the rules for breaking a glass with your voice?

So, this morning I woke up and remembered something I discussed about with one of my friends: Can human voice really break a wine glass? So I looked it up and after checking many websites and ...
-1
votes
1answer
929 views

Find the center of mass of a hemispherical shell

Problem: Find the center of mass of a hemispherical shell of constant density and inner radius r1 and outer radius r2. Attempt at Solution: Let the hemisphere be in the region $z>0$. By symmetry, ...
2
votes
1answer
106 views

Can sound frequency create more ideal conditions for fire?

You may have seen the recent story of a device that engineers claim can extinguish flames using sound frequency. An older article loosely explains the theory behind how this works: Sound travels ...
-1
votes
2answers
67 views

Can we relate volume to amount of matter?

Is volume the amount of matter in a body?If so, one kilogram water should have the same volume in its gaseous form. If we think of it, there is more space between the molecules of water in gaseous ...
3
votes
3answers
2k views

How can I measure the volume of a balloon?

I'm working on a project and I need to measure the volume of a balloon. In fact, I need to measure its radius. I want you to give me advice and ways of measuring it.
0
votes
1answer
118 views

Thermodynamics - internal energy

What would the curve that describes the change of internal energy ($U$) with the volume ($V$) be like if the change in the temperature is negative? My try: For a ideal monoatomic gas, we have ...
0
votes
1answer
55 views

How constant volume gas thermomether keeps the volume constant?

So the level of mercury on the left is being kept down by the pressure of the gas, correct? When the temperature rises, shouldn't the mercury level on the left go down? And when the mercury level go ...
0
votes
1answer
297 views

Difference between solid and gases thermal expansion

The coefficient of linear expansion is $$\Delta L = L \,\alpha \Delta T,$$ where $\Delta t$ can be the difference of any two temperatures. However, in volume expansion of gases, $$\Delta V = V ...
3
votes
1answer
2k views

How to calculate the volume of water in a certain amount of air, given the relative humidity?

If, according to the weather forecast, the current humidity is 90%, how can I calculate the volume of water that could be extracted from a certain volume of that air?
1
vote
1answer
1k views

Calculate Compressibility of water [closed]

I have 1 litre of water on 30 celsius, and there is a pressure of 10 mega psi affects on it. I want to calculate volume decrease that caused by pressure Thanks
-1
votes
1answer
5k views

What happens when ice melts? [closed]

Case 1: You take x litres of water and cool it to solid ice(say 0 degree) and measure the volume of ice as ...
0
votes
5answers
55 views

Particles passing through a surface

Today is the day I ask silly questions : The book says the particles passing through the surface $dS$ are the ones contained in the cylinder of volume $dS.v.dt.cos(\theta)$ but I really don't see ...
1
vote
2answers
159 views

What does volume means at the quantum level?

The volume of the electron is the space bounds in which it is contained says the @CuriousOne. But how can we define the volume in such a small range. If we immerse a cuboid into a vessel full of ...
2
votes
0answers
39 views

Does an electron occupy a definite volume? [duplicate]

The proton is about 1.6–1.7 fm in diameter. Quoted from Wikipedia. That is,The proton just occupies a definite volume or a definite space. But I can't find the radius of an electron in ...
0
votes
0answers
52 views

What happens when electromagnetically shunken coin is heated

The question is simple: What happens to coin/object that was electromagnetically shrunken by a coin crusher device is then heated until it (I asume) melts? Do I have misconception or not just ...
2
votes
0answers
155 views

Simple gas in cylinder modeling

I want to do a simple (physically plausible but not physically accurate) simulation of a gas in a cylinder as it works on or is worked on by a piston. Wikipedia gives a good example of an adiabatic ...
1
vote
2answers
289 views

Volume of Brillouin zone is the same as Fourier primitive cell?

In Kittel's solid state text, problem 2.3, he says that the volume of the Brillouin zone is the same as a primitive parallelepiped in Fourier space. Somehow I can't see why this is true. Can someone ...