1. ### Chemistry Chemistry equilibrium - Remove H2

It is desired to remove the molecular hydrogen present in a flask. What will be better to introduce, ##Cl_2## or ##Br_2##? Why? ##2 HCl <-> H_2 + Cl_2## (1) ##k = 3,2.10^{-14}## ##H_2 + Br_2 <->2 HBr## (2) ##k = 2.10^9## I thought about turning equation (1) to make the...
2. ### Small deviations from equilibrium and Lagrange multipliers

According to the book "Principles of Statistical Mechanics" by Amnon Katz, page 123, ##\alpha## must be such that ##\exp ( -\alpha N ) ## can be expanded in powers of ##\alpha## with only the first order term kept. Is this the necessary and sufficient condition for small deviations from...
3. ### Understanding rigid-body equilibrium problem

So I have this problem The soultion to the problem gives me this drawing But I don't understand what ##F_h## and ##F_v## is
4. ### Chemistry Ionic equillibrium

i am having a problem in understanding the question , what will be the volume of hcl ? and how is the reaction gonna take place ? please help me i am stuck on this problem for quite a long time.
5. ### Chemistry Solving for electron activity given pH and ratio of redox elements

I've written out the half reaction 8e- + 9H+ + SO42- = HS- + 4H2O and I know the logK = 4.25 (that's the constant mentioned in the prompt) I've written out the equilibrium statement of 10^4.25 = ([x^1/8]*[H2O^1/2])/([10x^1/8]*[e-]*[(10^-8.2)^9/8] However, from there, it seems like I have two...
6. ### Chemistry Finding the pH of this acid and its sodium salt solution

For finding the pH of the acid, I made use of the equilibrium law (or the law of mass action) to arrive at the degree of dissociation which I later used to get the [H+] concentration. I am stuck in finding the pH of the salt solution. ##CH2ClOO^- + H2O <---> CHClOOH + OH^-## Could you please...
7. ### Electrostatic force equilibrium

I was thinking that we can equate the electrostatic potential energy and the spring energy (as the force is similar to that of a spring so energy will also be 1/2kx^2 ) but i am not getting the correct ans but by equating the net force on one charge to kr i am getting the correct ans can...
8. ### Calculating a force on a member (Statics)

I isolated the member ABC and drew the free body diagram: α is then calculated using inverse tan: Tan-1=(6.25+15)/50=23.03 Then force of member BD on the joint can be found by sum of all moments around point A. Then Ax is calculated which is equal to BD×Cos(α)=235.2×Cos(23.03) Ax=216.48...
9. ### Why doesn't the amount of Cl increase?

Homework Statement Homework Equations Formula of Kp and Kc The Attempt at a Solution You will easily be able to identify that the reaction will proceed in the forward direction when some inert gas is introduced. So,my question is that why won't the amount of chlorine formed increase in...
10. ### How to find the normal force of a car jack lifting a car

Homework Statement A car is lifted vertically by a jack placed at the car's rear end 40cm off the central axis, so that the weight of the car is supported by the jack and the two front wheels. The distance between the front wheels is 1.60m, the distance from the axis connecting the two wheels...
11. ### Carrier concentrations

Homework Statement For silicon at T=300K with donor density ND=2×109cm−3, acceptor density NA=0 and ni=8.2×109cm−3, calculate the equilibrium electron and hole concentration Homework Equations n_0=\frac{N_D-N_A}{2}+\sqrt{\frac{N_D-N_A}{2}^2+n_i^2} p_o=\frac{n_i^2}{n_0} The Attempt at a...
12. ### Defining equilibrium and movement in pulley arrangements

Homework Statement I had to answer which of the pulley arrangements illustrated (see picture) is in equilibrium (the drawing went a bit difficult, please see all outer boxes as equal in size and the middle ones as well) I managed to answer that it is arrangement C, by finding out that...
13. ### Is P(atm)=P(gas)?

Homework Statement See this question. Homework Equations Pressure=Height*Density*Gravity The Attempt at a Solution I think P_atm=P_gas. I think so because for the two liquids(oil and Hg) to be in equilibrium the net force on them should be zero. And,since they are not getting displaced...
14. ### B My Third Post: Change of Intermolecular Distance?

Hello, Let us imagine a rod resting on a frictionless horizontal surface such that the rod is made up of 2 identical molecules. Let these molecules be named A and B from left to right. If we pull A to the left and B to the right with forces of equal magnitude, the rod must remain at equilibrium...
15. ### I Activity of daugther isotope in secular equilibrium

Consider chain of two radioactive decays ##A \to B\to C##. The equation that regulates ##N_B## is $${\frac {\mathrm {d} N_{B}}{\mathrm {d} t}}=-\lambda _{B}N_{B}+\lambda _{A}N_{A}$$ I can't understand why the activity of ##B## is get as ##\lambda_B N_B##, for example at page 20 here...
16. ### Equilibrium of a stiff plate on inclined planes

Homework Statement A thin stiff uniform rectangular plate with width L (L =AB) is lying on two inclined surface as shown in Fig. 3-1. The angle between the horizontal surface and the left inclined surface is α, and that between the horizontal surface and the right inclined surface is β. It is...
17. ### System of equilibrium, why won't the normal force apply?

Homework Statement Homework Equations The Attempt at a Solution I've resolved all the relevant forces (tension, weight, normal force), but upon looking at the mark scheme, there is no normal force to be resolved. Forgive me if I'm missing out on something obvious, but shouldn't there be a...
18. ### Does the angle of a beam fixed at two points affect the method?

Homework Statement if a beam fixed at two points is on an angle say 45 degrees from the x or y axis instead of running parallel to x axis in most questions does this effect calculations? The force acting upon it would be a load directly downwards Homework Equations N/A The Attempt at a...
19. ### Cube balanced at equilibrium about two different axes

Homework Statement A cube balanced with one edge in contact with a table top and with its center of gravity directly above the edge is in _______ equilibrium with respect to rotation about the edge and in _________ equilibrium with respect to rotation about a horizontal axis that is...
20. ### I [Stat Phy] What does exhausting the states of a system mean?

I was reading the *Statistical Physics An Introductory Course* by Daniel J.Amit and need some help to understand a certain passage: In an isolated composite system of two paramagnetic system: System a with ##N_a## spins and a magnetic field ##H_a ## System b with ##N_b## spins and a...
21. T

### Understanding Tension on a Pulley

Homework Statement Problem image: https://prnt.sc/gvhjso In this case I have to find the reaction forces at the point E (the Fx, Fy, and the Moment at point E) by using the given data. The 20kN forces at the load AC are concentrated, and are 1.8m far from each other. The tension of the cable is...
22. A

### I Triangle of Forces

Hey So I am still a beginner in Physics and work asked me today to calculate if a 63mm Bore Pneumatic Ram will do the required job. Anyway, so I know how to calculate the weight capacity the ram can handle if it is at a 90 deg angle however if the ram is on an angle then I am stuck. I need to...
23. C

### Finding forces in members of frames

Homework Statement I'm trying to solve for this problem below.How would you be able to get the force in member ID and GC? Find the reaction forces in member AFGH Homework Equations ∑M = 0 ∑[F][/y] = 0 ∑[F][/x] = 0[/B] The Attempt at a Solution I dismembered all of its parts but no matter...
24. ### Moment Equilibrium in terms of box weight

Homework Statement The board shown below is being held in equilibrium in the vertical plane by three smooth rods at A, B, and C Determine the magnitudes of forces at A, B, and C in terms of the weight of the body, W. Homework Equations Moment = f*r Here's a diagram The Attempt at a...
25. ### Effect of Temperature on Chemical Reaction Equilibrium

here is the question (part I): For part I, I need some assistance, I cannot figure out how to do the question. I know eventually what to do, it's just working out the equilibrium constants I'm having trouble with. So to start, I want to work out the K values at 600K and 800K, I do this by...
26. ### Latent heat and specific heat in insulated container

Homework Statement A 1.0kg of ice at 0◦C, 3.0kg of water at 0◦C, and 5.0kg of iron at temperature T are placed in a sealed and insulated container. cFe =400J/ kg◦C ,cWater=4200J/ kg◦C , cIce= 2000 J/ kg◦C latent heat for ice is 3.3×105 J . The equilibrium temperature is 20◦C. Homework...
27. ### Calculating equilibrium force

Homework Statement A human holds a ball of mass 8kg at his hand, so that the forearm is perpendicular to the upperarm. The distance between the elbow and the center of mass of the forearm is 0.15 meters, the distance between the elbow and the muscle is 0.05 meters and the mass of the forearm...
28. ### Statics: math check please

Homework Statement Homework Equations [/B] ΣFy = 0 ΣFx = 0 TanΘ = sinΘ/cosΘ...
29. ### Methane production and storage

Hello members, I wish to produce and "store" "Methane" gas. I wish to accomplish this task by conducting out a reaction between carbon-dioxide an water. I have my own source of energy and I completely understand that the reaction is endothermic. The reaction is: CO2 + 2H2O + energy = CH4 + 2O2...
30. ### Static equilibrium: need help setting up the equation

Homework Statement A rigid wire frame is formed in a right triangle, and set in a vertical plane as shown. Two beads, of weight W1 = 1.5 N and W2 = 2.5 N, slide without friction on the wires, and are connected by a cord. When the system is in static equilibrium, what is the tension in the...