Equilibrium Definition and 1000 Threads

Hello, Consider a cylindrical region (length dr, end area dA) at a distance r from the center of the sun Density =ρ(r) Volume = Length x area = dr.dA (How is the formula for volume of a cylinder works here?) Mass= Density x Volume = ρ(r).dr.dA Now, computing F(grav) =...

Homework Statement I am working on a project where I have to design and size an aquifer. There are two which either store hot or cold water for 6 months which is then pumped up to be used in either the summer or winter. The aquifer is going to be 80 meters under the ground. The rest is...

Problem: I've been working on my assignment and the purpose of it is to determine the concentration of a contaminant present in a sample of water. I've discovered the contaminant is ammonium phosphate with the levels of each being 200% higher than normal water. I obtained these results using...

Homework Statement Answers were told to us to be F = 2.91 N Ft1 = 13.32 N Ft2 = 3.36 N Homework Equations Fx = Ft2 cos(θ) - F = 0 Fy = Ft2 sin(θ) + Ft1 - Fg = 0 Torque equation -FgDg - Ft2D1x cos(θ) + Ft2D1y sin(θ) = 0 The Attempt at a Solution I plugged in all of the information i had...

Virtual work principle states: δW = \sum^{N}_{i=1}\vec{F}_{i}\centerdot δ\vec{r}_{i} And from this, we can see that if a system is to be in equilibrium we have δW = (\sum^{N}_{i=1}\vec{F}_{1} \centerdot \frac{\partial \vec{r}_{1}}{\partial q_{1}})δq_{1} + \cdots = 0 Where did q come...

Three forces -- in equilibrium or not? Hi. I am new to physics and need some help on this question asap. Did I get it right or is it wrong? Correct me if I am wrong. Thank you.

Homework Statement A diving board of length L is supported at a point a distance x from the end, and a diver weighing w1 stands at the free end (Figure 1) . The diving board is of uniform cross section and weighs w2. (Figure 1) Find the force at the support point. Find the force at the end...

1. What occurs during static equilibrium? 3. The net force and net torque on the object is zero. The acceleration of the object is zero too. Would velocity of the object also be zero? Or no because it has constant velocity?

I've drawn the following FBD (using D'alembert prinicple) [The N in my drawing is the F_A stated in the question] ---------------- Assuming my FBD has nothing wrong, am I right to say that I am free to choose my torque equation about ANY POINT? somehow my solutions vary depending on my point...

Homework Statement A uniform, 263-N rod that is 2.20m long carries a 225-N weight at its right end and an unknown weight W toward the left end (see attached figure). When W is placed 55.6-cm from the left end of the rod, the system just balances horizontally when the fulcrum is located...

I am familiar with the equation ΔG=ΔG°+RT ln(Q).But I can't derive it.We have to use the equation to derive nernst equation. So please help.

I have an air molecule moving because of a sound wave. f of sound wave = 500 Hz wavelength of sound wave = 0.68 m How fast is the air molecule moving in its equilibrium position? Is it in equilibrium at V max? Would this be where the position = 0?

Homework Statement A 0.241-kg particle undergoes simple harmonic motion along the horizontal x-axis between the points x1 = -0.349 m and x2 = 0.419 m. The period of oscillation is 0.511 s. Find the frequency, f, the equilibrium position, xeq, the amplitude, A. Homework Equations The...

Homework Statement A 0.500 kg mass is suspended from a spring and set into oscillatory motion. A motion detector is used to record the motion, and it is found that its velocity function is given by Vx(t) What are: a. the period of the motion; b. the amplitude; c. the maximum acceleration...

Homework Statement See attachment Homework Equations Let u be the angle between AC and AO and v the angle between BE and BD. Ta is the tension at point A and Tb is the tension at point B. The Attempt at a Solution Tried starting with the OAB body and got: -mg + Ta sin(u) + Tb...

Homework Statement Charge A and charge B are 2.2m apart.Charge A is 1.0C, and charge B is 2.0c. Charge C, which is 2.0C, is located between them and is in electrostatic equilibrium. How far from charge A is charge C. Homework Equations E = KcQ1Q2/r^2-------Electric force Formula where E...

Here is a text from my Physics Book : The net external torque on the object about any axis must be zero for it to be in rotational equilibrium. I divide the torques into two categories, anticlockwise and clockwise. (This approach works fine for 2-D objects but will it work for 3-D objects...

Homework Statement Homework Equations Ʃτ = 0 τ = rFsinθ The Attempt at a Solution I'm not even really sure where to start with this. My first thought was that it's not moving, so presumably the forces sum to 0. I also thought of treating the point where the net is exerting...

Homework Statement Here's a diagram of a rod that's free to pivot about the point indicated. Is it possible to make the right end of the rod push down, by pulling on the left end of the rod? If so, show on the diagram the direction that you would pull on the left end of the rod, and explain...

Homework Statement Diagram 4 shows a 2 kg mirror hung on a wall using strings of the same length . The mirror is in equilibrium state. a) On Diagram 4 , label the force that act on the mirror . b) Calculate the tension of the string , T that act on the mirror . c) Suggest a modification to...

Homework Statement A horizontal beam of weight W is supported by a hinge and cable as shown. The force exerted on the beam by the hinge has a vertical component that must be: Answer is nonzero and up. The pull P is just sufficient to keep the 14-N block and the weightless pulleys in...

Homework Statement Two ideal gases are separated by a partition which does not allow molecules to pass from one volume to the other. Gas 1 has: N1, V1, T1, Cv1 for the number of molecules, volume it occupies, temperature in kelvin, and specific heat per molecule at constant volume...

When making the Morse Potential graphs of diatomic molecules going through a transition, the excited state sometimes has a different equilibrium bond length. A visual example is here: http://en.wikipedia.org/wiki/File:Franck-Condon-diagram.png I was wondering how the average bond length of...

Homework Statement what magnitude of force applied horizontally at the axle of the wheel is necessary to wheel over an obstacle of height h = 0.108 m? The wheel's radius is r = 0.698 m and its mass is m = 1.71 kg. Homework Equations I know that in order to have a static equilibrium we...

equilibrium -- A rod influenced by multiple rope tensions Homework Statement Smooth and identical rod has a weight of P. The rod seems to be in equilibrium with X and Y which has a weight of P. What can be the weight of X according to the values below?(ip means rope) P , 6P or 9PHomework...

Hello, I was wondering if someone could explain part of the solution to this problem for me. http://img706.imageshack.us/img706/5517/disksproblem.png To the right is the Free Body Diagram of Disk E, and I can draw the forces on there well enough. But I really do not understand how they...

I'm studying vapor pressure and I'm having trouble to understand some concepts. Vapor pressure depends only on the temperature of the liquid in question right? For example, if we have a container with water at 30° C, it doesn't matter the experiment, would it ALWAYS be a vapor phase with...

Homework Statement A uniform solid cube, of edge 1m and weight 200N, rests on a rough horizontal plane. A light rod AB of length 1.2m is smoothly hinged at A to a point of the plane and B is in contact with a smooth face of the cube. The rod lies in a vertical plane perpendicular to...

Hi, I have simple question N2+3H2 = 2NH3 + heat How would the equilibrium position be affected if ammonia is removed from the vessel?, shouldn't it move to the left to produce more reactants and replace the ammonia? why does it move to the right?, because that's what my texbook says.

Homework Statement \dot{x} = -pxy + qx, \dot{y} = rxy - sy where p,q,r and s are positive constants (p does not equal r) Question is : Determine all the equilibrium points for the system of differential equations given above, expressing your answers in terms of p,q,r and s The...

Hi, I understand from calculation that the molar concentration of Pure water is 55.5 moles/Liter Then how come in equilibrium reactions when calculation the dissociation constant, we say that the concentration of water is 1 Molar? This seems like a huge difference to me? What is it I need...

Hi all, Why do the fermi level for electrons and holes coincide in equilibrium condition and why they separate as quasi fermi levels in non equilibrium situation?

Hi, I'm having a bit of difficulty deriving the time to max activity for the case of transient equilibrium for a parent-daughter. This is where I want to get to , tm = (1 / (λ1-λ2)) * 1n(λ1/λ2) I believe there is an alternative equation for tm as well expressed in terms of half-life...

Homework Statement I am trying to show that for a duffing oscillator described by x''+2g x'+ax+bx^3=0 with a<0, b>0 the equilibria at x=+- \sqrt{-a/b} are stable Homework Equations I used coupled equations, and the characteristic equation of a linear system The Attempt at a Solution...

Hello physics whizzes. How much force is required to raise an item weighing 5,000kg to a height of 50 meters in a frictionless environment? It seems that all you would do is F = MA = (5000) (9.80665) = 49,033.25 Newtons, and that the height is irrelevant assuming that the gravity stays...

Homework Statement Hello, I am required to determine the total number of micro states of a system in equilibrium within a certain value, 1/σ. The number of micro states for this system is given by, \Omega...

Hi, I just want someone to explain this table to me please, I am totally confused especially with the Change(mol). Question below:

Homework Statement Give the equilibrium concentration of majority and minority carriers and resistivity for Silicon which is doped with 3x10^{15} boron atoms/cm^{3} at 27°C. Homework Equations n_{o} = \frac{N_{d}-N_{a}}{2}+\sqrt{(\frac{N_{d}-N_{a}}{2})^{2}+(n_{i})^{2}} p_{o} =...

Hello, I have been trying to follow the start of these lecture notes I found online and I have having trouble understanding what is happening between two steps. The notes I am looking at are located: http://pillowlab.cps.utexas.edu/teaching/CompNeuro10/slides/slides16_EntropyMethods.pdf...

Homework Statement One mole of copper at a uniform temp. of 0 Celsius is placed in thermal contact with a second mole of copper which, initially, is at a uniform temperature of 100 Celsius. The pressure in the system is maintained at 1 atm. The two moles of copper are thermally insulated from...

Homework Statement A uniform strut of length, L and weight 780 N is free to pivot about point P where it is attached to the wall (see diagram) A weight W = 815 N hangs straight down from the end of the strut. A rope is attached to the same end as the load and the wall completes the support as...

Homework Statement A thin, square, conducting plate 50.0 cm on a side lies in the xy plane. A total charge of 4.00 x 10-8 C is placed on the plate. Find (a) the charge density on each face of the plate, (b) the electric field just above the plate, and (c) the electric field just below the...

Hey Guys, Well I am a freshman taking Physical Science and my teacher didn't do a good job explaining this question. http://prntscr.com/uf6tv <-- that's the problem and i numbered the 6 questions If you could answer those questions and explain how you got that it would be awesome! thanks

Homework Statement Consider a system in thermal equilibrium consisting of N particles that have 2 energy states E1 and E2 separated by an energy ΔE. Given that $$N_1 = \frac{N}{exp(-ΔE/k_BT)},\,\,N_2 = \frac{N exp(-ΔE/k_BT)}{1+exp(-ΔE/k_BT)}$$ show that in the case of the lowest energy...

Homework Statement Hello all, I just finished a question on equilibrium. I wish I could upload a diagram or something but I don't know how to get it from my Microsoft oneNote to here. But basically there is a mass held In equilibrium by two ropes. on the left is mass 2 and on the right is mass...

Homework Statement A spherical pendulum consists of bob of mass m attached to a massless rod of fixed length R. The end of the rod opposite the bob pivots freely (in two directions) about some fixed point. For the conical pendulum (θ=constant) case, show that the conical angle is stable...

Homework Statement I have a picture attached with this static equilibrium problem. (Solve system for Fac and Fab) Homework Equations Sum of x and y both=0The Attempt at a Solution I just don't have a systematic easy approach to solving these systems. Does anyone have one? From the picture...

Hello. I was studying the Semiconductor and I am confused with this diagram. I have attached the diagram. Please tell me briefly what does this diagram say. So that I could ask further. I have confusion with this diagram. I don't want to be specific so that you describe the whole diagram...

I came across Tolman's paper on the equilibrium distribution of temperature in gravitational field. He argues that in contrast to classical thermodynamics situations, in gravitational field, a fluid in thermodynamic equilibrium will not have the same temperature everywhere (as measured by...