Equilibrium Definition and 1000 Threads

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...

Let us imagine that there is a Massless spring with fixed at one end. Unloaded length = L Spring constant: = k Mass = 0The spring is at static Equilibrium Force: F Displacement: d F = k d, elongated length: L+d If I remove F, what will happen ? 1. Spring return to...

If a system is in a stable equilibrium state,its energy is maximum for fixed value of entropy ,the parameters and the amounts of constituents.Im wondering why this is true?Homework EquationsThe Attempt at a Solution

Homework Statement 1. Calculate the equilibrium dissolved oxygen concentration for each temperature if PO2 = 21% (this means that if atmospheric pressure is 1 atm then O2 pressure is 21% of that) Homework Equations K19.8/RT = Kp PV=nRT The Attempt at a Solution K19.8/RT = Kp K19.8 =...

Homework Statement Homework EquationsThe Attempt at a Solution Since the cylinder is in equilibrium ,net force and torque on it should be zero. I am not sure whether we are required to calculate force due to the two fluids as it seems to be a simple conceptual problem . I think I am...

Homework Statement The system shown in Fig. 2-6 is in static equilibrium. Use the principle of virtual work to find the weights A and B. Neglect the weight of the strings and the friction in the pulleys. Homework Equations Conservation of gravitational potential energy. The Attempt at a...

I am currently reading cosmology and I read the statement "... chemical potential which is nearly always negligible when processes are in equilibrium." So the current understanding I got of chemical potential is through the law: $$dE = - pdV + TdS + \mu dN.$$ Hence for processes which occur at...

Homework Statement Place a third charge q between two charges Q1 = -2Q and Q2= 3Q so they stay in electrostatic equilibrium. Knowing that the distance between Q1 and Q2 is equal L Homework Equations (KQ1Q)/(QQ1)2 = (KQ2Q)/(QQ2)2 3. The Attempt at a Solution Let's start by saying that i know...

Homework Statement Consider the diagram below. A 1000 kg block being suspended in equilibrium by cables c and a. Cable c is on a pulley which can vary the length of the cable. Write the constraints of equilibrium. Find the tension in each cable based on varying lengths of cable c between 1.2 m...

Homework Statement a spherical ball of mass = 5kg rests between two planes which make angles of 30 degrees and 45 degrees respectively with the horizontal . The system is in equilibrium . find the normal forces exerted on the ball by each of the planes . The planes are smooth . Homework...

I don't manage to get this task right. See the pictures. First i take point D and draw a free body diagram. Then i use the equation for equilibrium. I can then calculate the tension in the wires that goes from D to B and from D to C. I then take point B and draw a free body diagram, but all the...

2a+b⇌product if pressure is increased 3 times of the initial pressure the velocity of the forward reaction will be of___________ the previous velocity? Actually i got 9 times but the answer is given 27 times Can anyone please give the hint about it? Thanks in advance!

The ball of weight W is held in place as shown in the left figure by the inclined surface and the compressed spring. The FBD of the ball is shown in the right figure. Determine the force exerted by the spring on the ball, and the force exerted by the inclined surface on the ball in terms of the...

Homework Statement Hi I am new to Physics Forums and desperately need some help! This is my first class back since undergrad and my math skills have gotten a little rusty. I think that's where I am failing. Okay here goes: http://tinypic.com/r/2zqf04k/8 There is a 4 subsystem...

Homework Statement See: attached imageHow do we get the final equation? I'm obviously missing out on something..

Electrostatics Equilibrium Problem-It is required to hold four equal point charges +q each in equilibrium at the corners of a square. Find the point charge that will do this if kept at the center of the square? I am doing the basics of coulomb's law,can anyone explain this to me? I cannot do...

q1___________Q___________q2 10cm 10cm In the figure above the charge in the middle is Q=-3.1nC. For what charge q1 will charge q2 be in static equilibrium? Relevant equations I think that F=kq1q2/r^2 is relevant my attempt at a solution Since the ions are...

During my studies I failed to understand thermonynamics and compared the whole subject to black magic. This frustrated me a lot. Years later I tried to restudy it by myself reading sources with less conventional approaches. I had finally come to believe I could make sense of it. But re-reading...

I've been thinking about the building-design simulation, and am hoping that someone can point me toward more complete treatises/references, than this hobbyist impression. I'm trying to develop a mathematical outline of simulated deformation physics, with the hope of eventually creating a...

Recently, the properties of nonequilibrium many-body quantum systems have aroused great curiosity of physicists. Numerous papers have been published about this area. But how do we measure how far the system is from equilibrium states? There are several proposals have been published, for...

Edit: well this is frustrating, not sure why the itex things aren't working.. Edit2: I've attached a picture of the question at the bottom as well. Homework Statement The cohesive energy of a solid noble gas may be written as (See picture below) Derive an expression for the...

When two gases are mixed, if they are to be in thermal equilibrium, they must have the same average molecular speed. Why or why not?

1. I have a question regarding the equation ΔG° = -RT lnK. When solving for the equilibrium constant K, what is the relationship between the vapor pressure of each molecular compound in a reaction? ΔG° = Free energy change R = Universal gas constant T = Temperature K = equilibrium...

Homework Statement H2(g) + S(s) = H2S(g) Kc= 6.8x10^-2 If 0.2 moles of H2 and 1.0 mole of S are heated in a 1L vessel upto 90C, what will be the partial pressure of H2S at equilibrium? Can someone help me with this step by step?Homework Equations The Attempt at a Solution Kc = 6.8X10^-2 = x /...

Homework Statement When a 50-kg mass on a pulley is allowed to drop, the friction in the pulley creates a constant 200 N force upward. What is the tension in the rope? Homework Equations F (upward) = F (downward) The Attempt at a Solution I attempted this problem by assigning the...

Homework Statement A two component gaseous system has a fundamental equation of the form S=AU1/3V1/3N1/3 + (BN1N2)/N N=N1+N2 where A and B are positive constants. V is volume , S is entropy, U is internal energy, N is mole number. A closed cylinder of total volume 2V0 is separated into two...

Question: Two pulleys of masses 12 kg and 8 kg are connected by a fine string hanging over a fixed pulley as shown. Over the 8 kg pulley is hung a fine string with masses 4 kg and M. Over the 12 kg pulley is hung another fine string with masses 3 kg and 6 kg. Calculate M so that the string over...

Ensembles Figured it out thanks, next post:

Homework Statement The crane shown below has a mass of 4000 kg and a base of 3.4 m. The arm of the crane is 22 m and attaches to the center of the crane. If the arm is placed at an angle of 30°, what is the largest mass that the crane can hold off the ground without tipping? Homework...

Hi guys, I am a new user of QCM and I am having trouble reaching equilibrium. I have isolated the chamber from air flows and vibrations, the crystals are clean and all the other removable parts have been cleaned as well. The real problem is that sometimes I have managed to reach equilibrium...

Hi Everyone, I'm having some trouble with a problem concerning translational and rotational equilibrium. The question involves a balance with various masses suspended from it (see attached image). The question states that the counterweight is moved from 1cm away from the fulcrum to 2cm away from...

Hi everyone, In this paper ( http://pubs.acs.org/doi/abs/10.1021/la962131c ), the authors calculate the surface energy of polymer and the contact angle of various liquids on these polymers using a so-called "liquid - polymer equilbrium contact dsitance". I'm wondering how to calculate such a...

Homework Statement A force is applied to a box 60 degrees from the horizontal. The box weights 5kg. If the force is 120N, and the surface upon which the box rests upon is frictionless, at what rate does the block accelerate? Homework Equations Fnet = ma Fg= mg The Attempt...

Homework Statement A dilute solution of surfactants can be regarded as an ideal three-dimensional gas. As surfactant molecules can reduce their energy by contact with air, a fraction of them migrate to the surface where they can be treated as a two-dimensional ideal gas. Surfactants are...

Homework Statement Find the equilibrium separation between Diamond and Copper materials. Homework Equations Lennard-Jones force/unit area: p_a(z)=\frac{8w}{3z_0}\left[\left(\frac{z}{z_0}\right)^{-9}-\left(\frac{z}{z_0}\right)^{-3}\right] I need to find z_0 which is the equilibrium...

Homework Statement Two cylinders, that can rotate around their vertical axis, are connected with a spring as shown in the picture. Moment of inertia ##J## is the same for both and they also have the same radius ##R##. Distance between the axes is ##L##. Spring with constant ##k## is ##d## long...

A uniform vertical beam of mass 40 kg is acted on by a horizontal force of 520 N at its top and is held, in the vertical position, by a cable as shown. a) Draw a free-body diagram for the beam, clearly labeling all of the forces acting on it. b)Calculate the tension in the cable...

Homework Statement Calculate the hydroxide ion concentration: 16.5 mL of aqueous sulfuric acid at 1.5 M added to 12.7 mL of sodium hydroxide at 5.5M. 2. The attempt at a solution H2SO4 (aq) + 2 NaOH (aq) <--> 2 H2O (l) + Na2SO4 (aq) Hydrogen Concentration: (16.5 mL / 1000) (1.5 M) =...

Homework Statement A 200 g wood block is firmly attached to a horizontal spring. The block can slide along a table where the coefficient of friction is 0.40. A force of 10 N compresses the spring 18 cm. If the spring is released from this position, how far beyond its equilibrium position will...

Greetings everyone, I have recently been trying to generate some theoretical pump probe spectroscopy data. The typical way to do this is via third order time dependent perturbation theory and applying phase matching approximations / Rotating wave approx etc etc. There is however, no...

Homework Statement http://i.imgur.com/VFb5rwj.png Homework Equations The Attempt at a Solution First, I drew the FBD for the system, one horizontal force at A, one force perpendicular to the beam at B, and the weight. Writing out the equilibrium equations: The sum of forces in...

Homework Statement A 30Kg neon sign is suspended by two cables, as shown. Three neighbourhood cats (5.0 Kg each) find the sign a comfortable place. Calculate the tension in each cable with the cats are in the positions shown. Homework Equations xCM = m1x1 + m2x2 ...

Homework Statement A uniform vertical beam of mass 40kg is acted on by a horizontal force of 520N at its top and is held, in the vertical position, by a cable as shown in the attached picture. a) Calculate the tension in the cable b) Determine the reaction forces acting on the beam by the...

i have this system x'=y-x3-xy2 y'=-x-x2y-y3 i worked it out and found the equilibrium point to be 0. how do i determine whether it is stable, assymp stable or not stable

Homework Statement Homework Equations Q = m c \Delta T \\ Q = m L_v \\ Q_{in} = Q_{out} The Attempt at a Solution m_s c_s (100 - 8) + m_s L_v = m_s c_s (100 - T) + m_m c_s (T) \\ 5778.06 + 33900 = 5778.06 - 62.805 T + 418.7 T \\ 33900 = 355.895 T \\ ∴ T = 95.25°C Answer should...

Homework Statement Ammonia gas decomposes to nitrogen and hydrogen spontaneously with an equilibrium constant, Kp = 5.9 x 109. Calculate the partial pressure of ammonia at equilibrium given that the partial pressure of nitrogen and hydrogen are both 2.7 atm initially. [Hint: If you need...