Questions tagged [volume]
The volume tag has no usage guidance.
270
questions
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What causes increment in volume when compressive forces are applied on an object
Doubt
When compressive forces are applied on a body, what causes increment in volume. According to me the volume should remain constant since the mass and density of body are constant.
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2 gallon tank pressurized to 100 psi connected with a tube to a tractor tire with only 30 psi
2 gallon tank pressurized to 100 psi connected with a tube to a large tractor tire with only 30 psi.
And the air does not move from tank to tire.
Why? Can anyone link a YouTube video to explain ...
1
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1answer
30 views
How does the melting ice cube in a glass of water doesn't change the water volume? [duplicate]
that's problably a very noob question, and answer that i found is: the water volume was always the same, what is kinda obivius, but doesn't seen enought to me. So I can't stop thinking, were did the ...
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0answers
15 views
Force acting on a cube on all sides [closed]
A metallic cube of length L is stretched out uniformly by force F normal to each of its faces. Given Young's modulus and Poisson ratio, what is the deformation in the cube?
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42 views
Can you plot irreversible but quasi static processes on a $pV$ diagram?
I've often heard that you can't plot irreversible processes on a $pV$ diagram, but what about in the case where you have a quasi static process with friction? There still exists a curve of ...
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9 views
Does multiple outlets (at same level on tank) from an overhead tank increase pressure?
I have a tank that is about 1foot high from my shower, however the pressure(or volume) isn't sufficient.
Is it possible to increase the pressure(or volume) at the showerhead by doing the following:
...
2
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2answers
51 views
When differential of $p$-$V$ $dW$ work equals $-pdV$?
The differential form of the first law takes the form $$dU=\delta Q + \delta W$$ or $$dU=TdS-pdV.$$ First, we know that $TdS=\delta Q$ for reversible process. So we can't say that $dU=\delta Q -pdV$. ...
2
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3answers
48 views
What causes volume of sound to decrease with distance?
I know about the inverse square law however I do not know why it actually decreases. Does it have to do with sound absorption, it runs out of energy so the vibrations lessen or as distance increases ...
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1answer
33 views
Why do some textbooks use $T$-$V$ diagram for temperature table instead of $p$-$V$ diagram?
I am confused about this thing. In the temperature table, the first column explains specific temperature and the second column explains corresponding saturation pressure.
From what I understand, if ...
0
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2answers
62 views
Why is tire pressure lower when parking and higher while driving (and not rise more when driving faster)?
I just noticed this whenever I park the car for a while, the tire pressure goes to a lower value on all tires, and whenever I start driving, it goes higher.
The difference is not so big, but it is ...
2
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1answer
106 views
Lost volume data of water and isopropanol mixtures [closed]
WHO has two recipes for disinfecting, based on ethanol and isopropanol (IPA). They typically start with an alcohol volume and then top it off with the other ingredients to 10 litre. One of the recipes ...
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1answer
30 views
Crossings in the $p$-$V$-diagram of Thermodynamic cycles
Today I was tasked with correcting and grading a first year thermodynamics exam and one student drew a very peculiar diagram for the Ericsson-cycle. In the p-V-diagram the isothermal expansion and ...
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2answers
125 views
Time period of piston performing SHM
Suppose I have a closed piston-cylinder system which contains an ideal gas,and it is being compressed adiabatically by the piston which has a vertical orientation,and in doing so,the piston is ...
0
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1answer
39 views
How can a Diesel motor be drawn on a $pV$-diagram?
Only quasi-static processes can be drawn on a PV-diagram, because during a quasi-static process thermodyanamic variables such as pressure $p$ and volume $V$ are well-defined. However, for example, the ...
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0answers
22 views
What Are The Physics and Air Pressure Effects of Extremely Large Bells
How would one go about figuring out the physical properties of when a bell is hit.
Can I parameterize the diameter of the bell, its height, and the kinetic force of the knock to get the volume in ...
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0answers
10 views
How does the distribution of entropy in the expanding universe evolve? [duplicate]
Also, Is the entropy divided by the volume of the (observable) universe increasing with respect to time or is that number decreasing, unstable, or constant, or infinite?
3
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1answer
101 views
Intuition of $dV$ in $PdV$?
I seem to have some misunderstanding of $PdV$ in the first law of thermodynamics.
$$ P dV = T dS - d U $$
I have a ballon. I apply some work (or change the temperature inside the balloon). Now, ...
2
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1answer
54 views
Particle states per phase space volume of a quantum gas
Consider a quantum gas in a box with volume $V=L^3$ and temperature $T$, consisting of spinless bosons. Explain why the number $dN$ of "single-particle states" in a "momentum space volume" $d^3p$ is ...
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3answers
134 views
Boyle's Law and hot air balloon
A bit dumb question because it is really difficult to imagine it. :-
Pressure is force per area. Talking about gases, the pressure is said to be the force molecules exert on walls of let's say a ...
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2answers
87 views
What does it mean for the Lorentz Transform to preserve areas?
If we look at the Lorentz Transform from some frame $S$ to some frame $S'$ moving relative to $S$...
$$\begin{bmatrix}
\gamma & -\gamma v\\
-\frac{\gamma v}{c^2}& \gamma
\end{bmatrix}\begin{...
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0answers
22 views
Change in entropy due to the change in volume
If its given that $N$ no of Ideal gas atoms are in $V$ volume. What will be the change in entropy in units of $N\cdot kb\cdot\ln2$ when the volume is increased fourfold, i.e. $V \to 4V$, keeping ...
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34 views
Demonstration of comoving volume between 2 redshifts
1) I can't manage to find/justify the relation (1) below, from the common relation (2) of a volume.
2) It seems the variable r is actually the comoving distance and not comoving coordinates (with ...
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0answers
31 views
What is the volume inside the inner event horizon of a Kerr black hole?
(Dokuchaev 2011) found periodic orbits of particles and photons inside a Kerr-Newman black hole with a maximally extended global geometry. They orbit inside the inner horizon $r<r_-$ where the $r$ ...
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2answers
43 views
Pressure and volume [closed]
Currently, I am working on this experiment where I hit a balloon with a small object so that the pressure inside a balloon changes.
The pressure increased when I hit the balloon, but I need to ...
1
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3answers
81 views
Dilemma of volume displaced by an object
I have 2 questions, the second question is based on the answer of the first question
1.)When an object floats, is the volume of the object submerged and displaced water equal?
2.)So if volume ...
1
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1answer
138 views
What has mass but do not take up space?
Loosely speaking matter is anything that has mass and takes up space... so photon has no (rest) mass and I don't know if it takes up space but it already been disqualified due to failing to meet ...
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2answers
77 views
What is water's center of mass?
Suppose there is a cube filled with water of height $h$. Where would the center of mass be? I would assume that since water is denser where it is deeper, the center of mass should move toward the ...
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3answers
1k views
Can we change the volume of a wire by applying force on it in order to stretch it, if yes is there any way to calculate it?
Can we change the volume of a wire by applying force on it in order to stretch it, if yes is there any way to calculate it ??
1
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1answer
40 views
Semiclassical volume of a single photon
An electromagnetic plane wave propagating in the +z direction with $\vec{E} = E_0cos(\vec{k}\cdot\vec{r}-wt)\hat{x}$ and $ \vec{B} = \frac{E_0}{c}cos(\vec{k}\cdot\vec{r}-wt)\hat{y}$. Let us now model ...
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3answers
57 views
About an adiabatic stroke in the Carnot cycle
In one of the adiabatic stroke in the Carnot cycle, the temperature of the gas reduces from T1(to what it was initially heated) to T2(temperature of the surrounding).
How exactly does the internal ...
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1answer
35 views
If water vapor changes its phase, how is it possible to maintain specific volume?
I was doing my thermal engineering exercises when I encountered a problem. The problem specified a fixed and rigid container with a volume $V=0.17\ m^3$, as I have a $T-S$ diagram for water, they give ...
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1answer
31 views
Fluids mixture density prediction
As you know 100 ml of H2O mixed with 100 ml ethanol is not 200 ml
What is the official name of this 'volume loss'?
Is it possible, and if so, how, to calculate, before mixing, what the density of a ...
2
votes
1answer
173 views
What is the length of the yarn in a ball of yarn? [closed]
The image https://commons.wikimedia.org/wiki/File:Ball_of_yarn_10.jpg shows a typical ball of yarn. Such a spherical ball of radius $R$ has a volume $4ĻR^3/3$. The radius of the yarn is $r$.
How long ...
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1answer
48 views
Related to the Second Law
It is impossible to cross two adiabatic curves. Could someone better justify me why? Is it something related to the Second Law?
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135 views
Volume form in terms of the Levi-Civita Symbol
I'm currently reading Sean Carroll's book on General Relativity, and at some point he writes:
First notice that the definition of the wedge product allows us to write
\begin{equation}
\mathrm{d}x^...
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0answers
25 views
What is the volume of water in an inclined pipe
Diagram:
I have a tank of water T, which was filled with 2000l of water. At some point along the pipe connected to it, there is a leak, which is leaking at the rate of 400l/24 hours.
Valve d and j ...
0
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1answer
143 views
Work done to compress a liquid in container [closed]
Into a compressed container containing water with pressure p and volume V we want to pump additional water. What is the work done? Unlike in the ideal gas, the work cannot be simply found out using ...
2
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3answers
88 views
Why does PV work consider total pressure instead of net pressure?
In physics, we define work as: $$W = F_{net}Ćd$$
However, in physical chemistry, PV work is calculated as:
$$W = PĆĪV$$
Why is total pressure used instead of net pressure? For example, if a gas is ...
0
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1answer
33 views
Typical balloon volume-pressure law
I need to find the gas pressure required to make a balloon take a given volume, knowing the gas densities and atmospheric pressure. Is there a typical law/correlation that can be used to approximate ...
1
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2answers
70 views
How do you define volume for gases? [closed]
Straight forward question. If atoms forming a gas float far from each other, how can we assign a volume to it? if it is in a container, perhaps we'd say the atoms, or molecules, reach every corner and ...
0
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1answer
87 views
Black hole mass
It has been taught to us that since the black holes have finite mass, their gravitational force is also finite, which totally fits. The Black hole anyhow has a singularity at it's center which is ...
0
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1answer
64 views
Converting Gas volume to Liquid Volume
For a test setup, I need to set CO2 flowrate as 130Ā L/h but I do not have a flow measuring device to set it. So I made one device as mentioned below.
Once I set the flowrate, I will remove containers/...
2
votes
2answers
107 views
How can I compute the missing volume by looking at the pressure changes?
Disclaimer: I'm not in any shape used to deal with physics and forgive me in advance if this question is either out of scope of wrongly formulated.
I have a very practical problem. I have a container ...
2
votes
1answer
83 views
Can I tell whether a cycle is reversible or not by the $p$-$V$ diagram?
A thermodynamic process is reversible if the system remains in the equilibrium state throughout. That's what we are told in the book. My doubt is, though, can we judge whether a process is reversible ...
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1answer
108 views
Question about using Liouville's theorem to calculate time evolution of ensemble average
With the Liouville's theorem
$$\frac{{d\rho }}{{dt}} = \frac{{\partial \rho }}{{\partial t}} + \sum\limits_{a = 1}^{3N} {(\frac{{\partial \rho }}{{\partial {p_a}}}\frac{{d{p_a}}}{{dt}} + \frac{{\...
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0answers
31 views
Calculating infinitesimally small volume of a sphere in velocity space
This link (at the end of the page) is deriving the formula to calculate an infinitesimally small volume $dV$ on the surface of a sphere with radius $v$ in velocity space. It states that $dV = ...
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3answers
395 views
Shape of isotherms in $P$-$V$ phase diagram
Please explain the shape of the isotherms in this P-V phase diagram. In particular, why are the isotherms flat in the liquid-vapor region?
(image from Lumen Learning | Physics | Phase Changes)
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3answers
71 views
$pV$ work and Specific volume [closed]
I am working on a $pV$ work exercise. I am given $P_1$, $P_2$, and $V_1$; we can solve for $V_2$. I am also given mass. I am told that the $pV$ relationship is $pv^{1.2}=const.$, where $v$ is ...
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3answers
90 views
Energy Density is expressed in Liters, Liters of What?
When looking at energy density of batteries it is often expressed as Wh/L. For instance, Wikipedia says Lithium Ion batteries have a density of 250ā693 WĀ·h/L. Liters is supposed to express the volume ...
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2answers
195 views
What is the volume occupied?
What is the volume occupied by 1 mole of gas at $10^{ā10}$ torr, the pressure inside an āultra high vacuumā (UHV) chamber.
How do I solve this problem without being given the temperature?
