Equilibrium Definition and 1000 Threads

Homework Statement A liquid is in equilibrium with its vapor at its boiling point. On an average, the molecules in the two phases have equal: (A) inter-molecular forces (B) potential energy (C) total energy (D) kinetic energy Homework EquationsThe Attempt at a Solution I know (A) is wrong as...

Homework Statement The lower end of a uniform beam is attached to a vertical wall by a frictionless pivot. The beam extends away from the wall and upward, making a 62° angle with the wall, and it is held in place by a horizontal wire attached from its upper end to the wall. The wire's length...

The goal is to determine the relative abundance of the ions using the spectrophotometer. As far as I understand, to determine the relative (or absolute) concentration of a coloured ion in solution, one must have the absorbance/transmittance of the solution at multiple wavelengths. Once the...

Hi everyone. So I have been learning about equilibrium recently in class... and suppose I have the following reaction: A(s) + B(aq) <-----> C(aq) + D(g) [Note: in parentheses, I indicate the state of my substances] So I was told recently that pulverizing my solid "A" would not change the...

Homework Statement Hi, I was working on a homework problem and could not resolve it. The problem reads as follows: A ladder that weighs 240N rests against a frictionless wall at an angle of 60 degrees from the ground. A 600-N man stands on the ladder three-fourths of the distance from the...

Homework Statement A light inextensible string of length l hangs on two pegs attached to parallel walls separated by a height. A small frictionless pulley of weight Wp is attached to a block of weight Wb. When it is placed on the string, the string becomes taut and pulley runs on the string...

Homework Statement I understood the fact that since the density of solids and liquids remain constant in a reaction therefore the active mass must be a constant.But why is it that we take it as unity. Is is some kind of coonverntion,or is there a reason behind it? Homework EquationsThe Attempt...

The question asks: Recall that you observed very little corrosion occurring on the iron nail immersed in NaOH(aq) solution. This observation is difficult to explain from an electrochemistry perspective since electrochemistry principles predict a spontaneous reaction that should cause...

Hello, every one! I'm studying the Section 9.2 - Phase Equilibrium of "Classical and Statistical Thermodynamics" written by Carter. In equation (9.21) and (9.22) He said: dS_{A}=\frac{1}{T_{A}}(dU_{A}+P_{A}dV_{A}-\mu _{A}dn_{A})-----(9.21) dS_{B}=\frac{1}{T_{B}}(dU_{B}+P_{B}dV_{B}-\mu...

Guys, I'm studying about Le-chatelier's principle and the topic is effect of temperature. I just went through it and found a difficulty that why K values changes i.e why the equilibrium constant changes as in other effects like changes in concentration, pressure,etc the K values remains constant.

Dissolve a salt containingCr2O72- and an "inert cation" in water, would the following equilibrium occur in appreciable quantity? Cr2O72-+OH-⇔2CrO42-+H+ If it does occur, I suppose the acidity of the water would affect the equilibrium constant (or at least the relative concentration of the...

Hi guys! I would really need some help with a problem I have over here: how do I you get the equations of equilibrium for the scheme in picture of the single degree of freedom system? I am having some trouble understanding why I have m1*Hc*(H*theta_0) mostly, but also about why I have moment of...

Homework Statement Find the value of W to maintain equilibrium Homework EquationsThe Attempt at a Solution I have split the system into two, creating a triangle. From this I have a right angle triangle with an adjacent of 2m, opposite of 0.6m and an hypotenuse of 2.088m (calculated through...

Homework Statement The equilibrium constant, Kp, for the following reaction is 0.636 at 600 K: COCl2(g) CO(g) + Cl2(g) Calculate the equilibrium partial pressures of all species when COCl2(g) is introduced into an evacuated flask at a pressure of 1.73 atm at 600 K. Homework Equations...

Why is rotational equilibrium condition independent of origin about which torques are taken?

I am trying to back-calculate the greenhouse effect on planetary equilibrium temperature for Earth (in the hope I can then attempt applying it to other calculations.) I know that the actual equilibrium temperature of Earth is 287.89K, +33K above the calculated equilibrium temperature: Teq = (Q...

Homework Statement A pole supporting a pedestrian and traffic light is shown. Neglecting the weight of the cables. Find the tension in the cables and and the support reactions at A,B,E. Mass of traffic signal 20kg Mass of pedestrian signal 10kg Mass of beam BCD 5kg center of gravity C Mass of...

I am thinking of a time period between two events: 1. After the annihilation of most protons/neutrons with all anti-protons/anti-neutrons, and 2. Before the annihilation of electrons and positrons. During this period the temperature decreases from T1 to T2. T1 is the highest temperature at...

Homework Statement Bromothymol blue is an acid-base indicator. When in solution, it forms the following equilibrium: HInd(aq) ⇌ H+(aq) + Ind-(aq) What side of the equilibrium is favored while the solution is in the bromothymol blue bottle?Homework Equations Keq = [(C)c(D)d]/[(A)a(B)b] The...

Is anyone familiar with these terms or the experiments involved? I have a lot of questions regarding them. Thank you guys.

Homework Statement Solve for the forces P and N acting on an object in equilibrium on an inclined plane. Weight=10N, angle is 30 degrees http://blob:https%3A//www.physicsforums.com/d431a152-5681-411b-ba57-809320539165 Homework Equations Trigonometry, i.e. sin, cos, tan rules. The 'Z' rule...

Hi ! So a friend and I were solving some mechanics problems in class today. And we came across a pretty funny mathematical paradox. So basically we tackled the problem in different ways...but we ended up with different equations...and none of us could prove the other wrong ! So here goes... The...

Hi. Assume a rock lying on the ground. Furthermore, let's assume both the rock and Earth to be rigid bodies. I'm a bit confused about force equilibrium and Newton's 3rd law here. There's Earth's gravity acting on the rock, and by Newton's 3rd law (or just by looking at the law of gravity) the...

Hi, I need some guidance on the following problem, please. A daredevil attempts to walk the full length of suspended. A 20 kg wrecking ball hangs at the end of this uniform beam of length 4 m and mass 10 kg and is attached to a hinged wall at an angle of 53 degrees. A cable attached to the wall...

Homework Statement Homework EquationsThe Attempt at a Solution [/B] 8) The mass is in static equilibrium meaning the sum of all the forces acting on it are equal to 0. Both sides are holding have the same tension because they have the same angle. SINΘ = (Opposite) / Hypotenuse = Hypotenuse...

Homework Statement Homework EquationsThe Attempt at a Solution I had someone help me with this problem (not on here) and their process and units don't seem to match to me. Or is this correct?

Homework Statement A trailer carrying a boat is supported by a scale which initially reads 48 kg. The boat (and therefore its centre of gravity) is moved 0.15 m further back on the trailer. The scale now reads 37 kg. Find the mass of the boat (Ignore the 6.0 m distance because it was not given...

Homework Statement Using Airy's Model of isostatic equilibrium, solve for the average anti-root height due to the ocean and the average density of the upper mantle. given info: ocean depth avg = 4km ocean crust is 10 km thick avg continental crust if 40 km thick avg all crust is the same...

Homework Statement As I reading this article I conflict with a problem, I never find the meaning of Figure 3(b). the paragraph below the figure illustrated it but I couldn't find what it want to say. every help will be a appreciated. Homework EquationsThe Attempt at a Solution

Homework Statement So a little background before stating the problem: During a lecture a couple weeks prior to lab, the instructor did an example where we were told to find the max height of a ball launched upwards by compressing a spring. In order to calculate that, he showed that E1 is the...

Hello, Could somebody help me finding the relation between the horizontal force, the weight acting vertically, and the slopes Angle (same for both) that correspond to static equilibrium of the blue ball ? In a first step, I'd like to study this problem without considering friction at all. And...

Homework Statement This is more of a math question but: There are two particles fixed in place: a particle of charge +8q at the origin and a particle of charge -2q at x=L. At what point (other than infinitely far away) can a proton be placed so that it is in equilibrium Homework EquationsThe...

I have seen something to this effect stated dozens of times on the internet : "..because the deuterons and the protons are exchanging so quickly, you will end up with a statistical distribution: 25% H2O, 25% D2O, and 50% HDO." They are referring to a sample of water which is 50 atom %...

Problems stated in attached pictures.So could someone explain me what am I doing wrong here this is solution for the example a) . I tried it twice and I am getting wrong results. Thanks in advance.

Assuming that we have a chemical plant which produces methanol through the following equations: CH4 + H2O <--> CO + 3H2 CO + 2H2 <--> CH3OH CO2 + 3H2 <--> CH3OH + H2O I know that with specific pressure, temperature and flow rates, I can produce reactions with specific equilibrium constants. Are...

Homework Statement Its said that there is no Net current in a PN junction under equilibrium as the drift and diffusion currents cancel each other. We are talking about a Step junction at equilibrium. Homework Equations Its just a qualitative analysis. 3. The Attempt at a Solution [/B] The...

1. Homework Statement Homework EquationsThe Attempt at a Solution This is what I did: Since they said at equilibrium, the total no. of moles is (2+x), so P and Q should have 1 mol each at equilibrium. So P and Q are in 1:1 ratio, but how do they know x is 1 ? Ans is B

Homework Statement The amplitude of vibration of a mass on a horizontal spring experiencing SHM is = 0.13m. The mass is 85g and the force constant is 55N/m. a) What is the maximum elastic potential energy of the system. b) Find the speed of the mass when it's position is x = 7.4cm from the...

Question: A uniform meter stick off mass Ms = 100g is supported by a pivot at its 35 cm mark. When an unknown mass is suspended from the 10 cm mark, the system is in equilibrium. What is the value of the unknown mass? Given: Pivot point at 35 cm, and mass of meterstick = 100g. Attempt: Do...

Homework Statement The 1.1m bar is supported by a ball and socket support at A and 2 smooth walls. The tension in the vertical cable CD is 1kN. Draw the Free Body Diagram of the Bar. Determine the Reactions at A and B. Homework Equations Equillibrium equations. Perhaps the vector...

I've been asked to find the final temperature of different in an insulated container. A combination of 0.25kg water at 20C, 0.4kg aluminum at 26C, and 0.1kg copper at 100C are combined, and allowed to come to thermal equilibrium. Finding the equilibrium temperature for two substances is...

This is not actually a homework assignment, but something I decided to try in my own time. I wanted to find the radius from a star at which a solar sail would be held at equilibrium (radiation pressure = gravity), given mass per unit area and stellar luminosity at a reference radius. So I...

Homework Statement Which side does the equilibrium favour? Homework Equations Equilibrium favours weak acid or weak base (I don't know why :frown:) The Attempt at a Solution Using the given pka values, since the reactant is the weaker acid, reactants are favoured. (Backward reaction is...

Homework Statement What will happen when a large amount of water at 0 C is mixed with ice at - 20 C? Assume ideal conditions. Homework Equations N/A The Attempt at a Solution I think the ice will rise in temp (without melting) but no new ice will be formed. Is this right?

Homework Statement I am given the forces on picture and I´m asked to find the reactions on both supports. I see they are pin supports so they ask me for 4 unknowns. Homework Equations Sum of forces in both directions equal to zero Sum of torques wrt a convenient point equal to zero THREE...

Homework Statement Hello there, this is my first thread here ! I've been trying to solve an exercise from my statics course and just couldn't get anywhere. Basically it's a system of two springs connected by a rope, and each spring is attached to a cylinder (Both Cylinders have same mass). The...

1. Homework Statement In the picture Homework Equations In the picture The Attempt at a Solution In the picture My question is .. Why in Fx has sin and Fy has cos ?

in the Haber process (N2 + 3H2 ⇔ 2NH3), if there are 2mol of N2, 3mol of H2 and 1mol of NH3, how do I know that the system is not in equilibrium and which direction will it shift?

Hi, Suppose a force of 5N is being applied to a 5kg block and the force of friction from the surface on which the block is in motion is 5N as well. The Net Force of the block is 0N, thus the block is not accelerating and is moving at a constant velocity. The question I have is, how to...

35g of h2o(g) at 380K flows into 300g of h2o(l) at 300K. Cp(l)=4.18kJ/K*kg and ΔH(condensation)= -2257kJ/kg. I need to calculate the final temperature when the system reaches equilibrium. Is the heat capacity for the h2o gas different than h2o liquid? Can you calculate heat capacity using...