What is Equilibrium: Definition and 1000 Discussions
Thermodynamic equilibrium is an axiomatic concept of thermodynamics. It is an internal state of a single thermodynamic system, or a relation between several thermodynamic systems connected by more or less permeable or impermeable walls. In thermodynamic equilibrium there are no net macroscopic flows of matter or of energy, either within a system or between systems.
In a system that is in its own state of internal thermodynamic equilibrium, no macroscopic change occurs.
Systems in mutual thermodynamic equilibrium are simultaneously in mutual thermal, mechanical, chemical, and radiative equilibria. Systems can be in one kind of mutual equilibrium, though not in others. In thermodynamic equilibrium, all kinds of equilibrium hold at once and indefinitely, until disturbed by a thermodynamic operation. In a macroscopic equilibrium, perfectly or almost perfectly balanced microscopic exchanges occur; this is the physical explanation of the notion of macroscopic equilibrium.
A thermodynamic system in a state of internal thermodynamic equilibrium has a spatially uniform temperature. Its intensive properties, other than temperature, may be driven to spatial inhomogeneity by an unchanging long-range force field imposed on it by its surroundings.
In systems that are at a state of non-equilibrium there are, by contrast, net flows of matter or energy. If such changes can be triggered to occur in a system in which they are not already occurring, the system is said to be in a meta-stable equilibrium.
Though not a widely named "law," it is an axiom of thermodynamics that there exist states of thermodynamic equilibrium. The second law of thermodynamics states that when a body of material starts from an equilibrium state, in which, portions of it are held at different states by more or less permeable or impermeable partitions, and a thermodynamic operation removes or makes the partitions more permeable and it is isolated, then it spontaneously reaches its own, new state of internal thermodynamic equilibrium, and this is accompanied by an increase in the sum of the entropies of the portions.
Homework Statement
I am stuck on this problem for my mechanics class. Please help me.
Determine the force in each cable and the force F needed to hold the 4-kg lamp in the position shown. Hint: First analyze the equilibrium at B; then, using the result for the force in BC, analyze the...
Homework Statement
Here is the problem that I am stuck on in my mechanics class.
https://lh4.googleusercontent.com/ygXVjNfI4iP8xVpEjhxXZlWlDqg_VrM2gCVFLyomOVwWCfcLU78mIcPEc7hEzUqBoACIiQ=w1210-h506
Homework Equations
F=-kx
The Attempt at a Solution
See the attached picture of my work...
Homework Statement
http://www.sumoware.com/images/temp/xzebnqpmgdnohmgo.png
An isosceles-triangle-shaped ladder like the picture above, has a negligible mass. A man with mass m kg climb the ladder till the height is 3 meter (see picture above).
Determine the tension of the link (at...
I own a landscaping business with accounts paying regularly. If I add 5 new accounts a week and on average an account stays a customer for one year before quitting, what would my equilibrium number of accounts be? How long to reach equilibrium? how many do I need to add per week to maintain at a...
Homework Statement
A heavy uniform cylindrical drum is placed, with its axis horizontal, on a slope inclined at an angle α
to the horizontal. It is prevented from sliding or rolling down the slope by a triangular wedge. The weight of the wedge is negligible compared with the weight of the drum...
How can Universe be at equilibrium when the FRW metric has no time-like Killing Vector?Request: Please, move this into Cosmology thread... :( Mistakenly I posted it in HEP
Homework Statement
Place 0.150kg (including the mass of the hanger) at a position somewhere between 0 degrees and 90 degrees. (I chose 45 degrees for this problem.) Place the second pulley at exactly 180 degrees and the third pulley at exactly 270 degrees. Determine how much mass you must place...
Homework Statement
Without adding any Chromium based compounds, how would you manipulate the above equation to produce more CrO42- ions? Be sure to use chemical equations to show the answer.
Homework Equations
2CrO42- (aq) + 2H3O+ <--> Cr2O72-(aq) + 3H2O (l)
The Attempt at a Solution
So my...
Homework Statement
A particle of mass 3m is located 1.00 m from a particle of mass m. You put a third mass M so that the net gravitational force on M due to the two masses is exactly zero. Is the equilibrium of M at this point stable or unstable for points along the line passing through M and...
Homework Statement
The problem is #12 found here: https://www.aapt.org/physicsteam/2013/upload/exam1-2012-unlocked-solutions.pdf.
A uniform cylinder of radius a originally has a weight of 80 N. After an off-axis cylinder hole at 2a/5 was drilled
through it, it weighs 65 N. The axes of the two...
Homework Statement
Two masses: m1 = 45 kg, m2 = 12kg.
m1 (45kg) sits at rest on a table top with static friction co. 0.45, kinetic friction co. 0.35.
m2 is suspended in the air. m2 is attached to m1 by a massless wire hung over a frictionless pulley
Homework Equations
FBDs, net force...
Homework Statement
Homework EquationsThe Attempt at a Solution
I'm not sure about which topic it is asked. I think it's something about the centre of mass . Because the statement " The pole and the box do not change form" . The answer is
(1 + tan Θ)/(1 - tan Θ)
Hi,
I've been working with equilibrium modelling in bleach plants of kraft mills in order to find areas likely of being subjected to mineral scale deposits. This has been rather successful - and it's been done successfully be many people before me.
However, now I am interested in applying...
So I'm not too sure about the answer to this question: explain why it is advisable to add water to an overheated automobile engine only slowly, and only with the engine running?
So if something is overheating, it makes sense to want to cool it. Since the water's temperature is less than that...
Homework Statement
A horizontal scaffold, of length 2.00 m and uniform mass 50.0 kg, is suspended from a building by two cables. The scaffold has dozens of paint cans stacked on it at various points. The total mass of the paint cans is 80.0 kg. The tension in the cable at the right is 830 N...
I was thinking about this:
Let's consider a dissociation of some chemical that can run in both directions:
AB\rightleftharpoons A^{+}+B^{-}
Dissociated form is soluble in a solvent and undissociated form is not - it precipitates.
Then the reaction proceeds to the left much faster than to the...
Homework Statement :-Why in equilibrium equation of potassium dichromate and chromate give below (in point 2.Relevant equations )there is H2O with dichromate ion but not with chromate ion, rather 2 hydrogen cation is present?[/B]Homework Equations [/B]The Attempt at a Solution :-I think it is...
I'm currently reading about the Boltzmann equation, used for the early Universe.
The equation I end up with, after some simplifications is the following:
\begin{equation}
a^{-3}\frac{d}{dt}\left(n_1a^3\right) = n_1^{(0)}n_2^{(0)}\langle\sigma v\rangle\left[\frac{n_3 n_4}{n_3^{(0)}n_4^{(0)}} -...
Kc1 = (5.8*2/5)^2 / (14/5)(1.4/5) = 6.865
6.865 = [HI]^2 / (45/253.8/100)(0.5/2/100)
[HI] = 5.52x10^-3 M
mass no of HI = [HI] x (126.9+1) x 100 = 70.6g
is it correct?
And how to do 3bii
I GOT 3bi Kc2 = [HCl(g)]^2/ / Kc(1) [H2(g)] [Cl2(g)]
So you take some boiling water and drop a metal cube into it and the cube will reach the temp of the water. Or you leave some hot water out on a desk and the water will eventually become room temperature, right?
Then why, in the summer time, does the inside of the car get way hotter than the...
Homework Statement
A seesaw with a mass of 5 kg has one block of mass 10 kg two meters to the left of the fulcrum and another block 0.5 m to the right of the fulcrum. If the seesaw is in equilibrium,
A. find the mass of the second block.
B. find the force exerted by the fulcrum
I have trouble...
Homework Statement
I have a question about the following question:
Firstly, shouldn't there be a normal force for each hand (part a), but here they treat it as one normal force.
Also in part b, why isn't the torque for Fn1h = 0? Since that is the pivot point, isn't the moment arm zero?
Homework Statement
Homework Equations
After creating a FBD and analyzing the forces, I get the equation for the angle as
## tan \theta = \frac{k q^2}{m g r^2} ##
The Attempt at a Solution
[/B]
I have tried to find a way to find the distance between the charges ## r ##, but the only way I...
Homework Statement
A uniform 300-kg, 6.0 M long, freely pivoted at P, as shown in the figure. The beam is supported in a horizontal position by a light strut, 5.0 M long, which is freely pivoted at Q and is loosely pinned to the beam at R. A load of mass is suspended from the end of the beam at...
Consider a pendulum in it's balance point hanging from ceiling. It can swing in all the directions in the space. The pendulum can only swing in a sphere(the string can't bend). Now, is it possible to release the pendulum in a particular height and with a initial condition that in the first...
Homework Statement
Given: The friction between the block with mass 11kg and the wedge with mass 22kg is 0.48. The surface between the wedge with mass 22kg and the horizontal plane is smooth (without friction). The [A][/g] = 9.8m/[/2]. A Block is released on the incline plane (top side of...
Homework Statement
A 3.50-kg block of iron initially at 8.00 × 10^2 K is placed on top of a 6.25-kg block of copper initially at 4.00 × 10^2 K. Assume the blocks are thermally insulated from their surroundings but not from each other and that they constitute a closed system.
How much energy is...
Suppose we have a game, played in which Alice and Bob play mixed strategies:
(sorry for the dots, but I don't know how to put a table or tab spacing in this text box)
..............Bob
..........Dove, prob q......Hawk, prob (1-q)
...Dove , prob p......(2,3).........(4,5)
Alice
...Hawk, prob...
Homework Statement
A child of mass m is supported on a light plank by his parents, who exert the forces F1 and F2 as indicated.
Find the forces required to keep the plank in static equilibrium. Use the right end of the planks as the axis of rotation. ( Answer: F1=(1/4)mg, F2=(3/4)mg )...
Hello
I got to thinking about temperature when i prepared a lecture for my high school class. For a monoatomic ideal gas the temperature is proportional with the average kinetic energy of the atoms. For a diatomc gas we also have rotational energy (vibrations assumed to be freezed out), and for...
Hi,
I must calculate how much CO2 has to be removed from the water (pHs=7.2) to obtain equilibrium
Given concentrations:
HCO3-: 223 mg/L
CO2: 60 mg/L
pH: unknown
SI: unknown
What is meant by equilibrium? (ph=7?) Please advise how to tackle this problem
Homework Statement
The question are included in the picture that are uploaded. So i know that for these systems to be at equilibrium, the net force in the x and y-axis must equal to zero. I wanted to write in the question and the diagram but i don't know how else to put it.
Homework Equations...
HF(aq) ↔ H+ + F-
Determine equilibirum concentrations with Initital concentrations and Kc.
Kc = 7.2 x 10-4
[HF] = 1.00M
[NaF] = 0.50M
I understand how to do an ICE table and put together questions, but what do you do with [NaF] when it is not part of the chemical equation? How to I factor it...
Based on the very basic understanding on enzymes I have gained from Year 12 Biology and Chemistry, I don't undesrtand why the enzymes specific shape also helps the reverse reaction. I guess my trouble would be due to the simplified diagrams I've seen from Biology, where only the forward reaction...
I am trying to set up an equation relating the mechanical energy in a hydropower plant to its electrical output. What I picture is the relation between the energy input from the moving water, to the rotational energy of the turbine to the electric output of the generator.
I know I can calculate...
Homework Statement
A 6.0 m bar is supported by a fulcrum at 3.9 m from the left end. There are loads applied to each end of the bar. The load at the left end of the bar is 468 N. What load in Newton should be applied to the right end of the bar to create equilibrium?
Homework Equations
M=Fd...
Homework Statement
Two identical, uniform beams weighing 260 N each are connected at one end by a friction-less hinge. A light horizontal crossbar attached at the midpoints of the beams maintains an angle of 53 degrees between the beams. The beams are suspended from the ceiling by vertical...
In a recent class, my instructor covered the Kinetic Theory of gases. My question is in regard to the theory which states
1) The size of the individual molecues in a gas are so small that their volumes can be considered negligible.
The instructor then mentioned that the paticles in the gas can...
Homework Statement
The answer is to be given in terms of L and w. The picture shows a beam of weight w and various blocks on it also each of weight w. It also shows the gravitational force acting downward on the center of gravity of the beam. The beam rests on a triangular pivot point.
2...
It has been a bit since I took chemistry, but I have been wondering something, and can't seem to remember. Let's say that I have the following:
Fe3+ + SCN- <-> FeSCN2+
How can I calculate the point where Fe3+ concentrations become effectively zero? That would say, if I know that I have 1M Fe3+...
∑Homework Statement
You are designing the crosspiece for the A-frame structure in the figure below. Beams AB and AC are 5.00 m long and have a mass of 375.0 kg each. How much tension must the crosspiece EF withstand? Assume that the mass of the crosspiece and the friction at points B and C are...
Homework Statement
A solid hemisphere with radius b has its flat surface glued to a horizontal table. Another solid hemisphere with radius a rests on top of the hemisphere of radius b so that the curved surfaces in contact. The surfaces of hemispheres are rough, meaning no slipping occurs...
Homework Statement
A mass (m = 1.20 kg), originally at rest, is attached to one end of an unstretched spring (k = 790 N/m) and the other end is fixed to a wall. The mass is then pulled with a constant force to stretch the spring. As a result, the system comes to a momentary stop after the mass...
Homework Statement
You are designing the crosspiece for the A-frame structure in the figure below. Beams AB and AC are 3.35 m long and have a mass of 350.0 kg each. How much tension must the crosspiece EF withstand? Assume that the mass of the crosspiece and the friction at points B and C are...
Homework Statement
A rope of negligible mass is stretched horizontally between two supports. When an object of weight 3160N is hung at the centre of the rope, the rope is observed to sag by 35.0cm. What is the tension in the rope?
Homework EquationsThe Attempt at a Solution
[/B]
Sum of...
In statistical mechanics the boson distribution function has the well known form
##f = \frac{1}{e^{E/T} - 1},##
(in the special case of zero chemical potential). As one considers the non-equilibrium variant this generalize to
##f = \frac{1}{e^{\frac{E}{T(1+ \Theta)}} - 1},##
for some function...
Consider the following generic equilibrium:
aM + bN ⇌ cO + dP
An equilibrium constant, K, can be defined as:
$$K = \frac{[O]^c [P]^d}{[M]^a [N]^b}$$
But couldn't we also define another equilibrium constant similarly with coefficients that are in the same ratio as our original equation? For...
A triple beam balance, like the scales we use every week in lab, works using rotational equilibrium. If a 253 g mass is placed on the pan, 1 cm from the pivot, and there are three masses, 1 g, 10 g, and 50 g masses on the other side can be slid back and forth between 0 cm and 10 cm from the...
Hello,
I went through a problem in my reaction engineering textbook, and solved them correctly by basically mindlessly plugging into the equation, but now I wanted to get some help interpreting the results.
So we had a reversible, elementary gas phase reaction that is isothermal and isobaric...