Equilibrium Definition and 1000 Threads

Homework Statement Find the angle Theta so that the system is in equilibrium Mass of each block: 2 Kg Mass of ring: 4π Kg Homework Equations Static equilibrium: Rotational equilibrium The Attempt at a Solution Static equilibrium: 2g + 2g + 4πg = Normal N = 4g + 4πg Taking...

Homework Statement Two monatomic ideal gases are in thermal equilibrium with each other. Gas A is composed of molecules with mass m while gas B is composed of molecules with mass 4m. The ratio of the average translational kinetic energies KA/KB is: Homework Equations KE=0.5xmxVavarage^2...

Suppose there is a test chamber containing liquid nitrogen. The container is insulated and only a small opening is there so that chamber is exposed to atmospheric condition. As the saturation temperature of liquid nitrogen is -196 degree Celsius at 1 atm pressure. chamber will remain at -196...

I just wanted to confirm whether the idea I have about vertical springs is correct or not. Suppose you have an ideal (massless) spring oriented vertically, and suspended from a block in the air, which in turn is mounted on a stand and placed on a desk. The distance from the desk (or the base of...

Homework Statement A board that is of length L = 6.0 m and weight W = 335.7 N rests on the ground and against a frictionless contact at the top of a wall of height h = 2 m (see figure). The board does not move for any value of greater than or equal to 65 degrees but slides along the floor if...

Homework Statement The 25-kg rectangular access door is held in the 90° open position by the single prop CD. Determine the force F in the prop and the magnitude of the force normal to the hinge axis AB in each of the small hinges A and B.[/B] Homework Equations ΣF=0 ΣM=0 [/B]The Attempt at...

1. The problem statement, all variables and given/known Homework Equations show that a hydrogen gas cloud at 10000K is about twice as optically thick at the Balmer limit compared with the Paschen limit. Assume that the H atoms are in Local Thermodynamic Equilibrium, the Gaunt factor is unity...

Homework Statement Using the total energy, solve for the equilibrium distance R0 α is given and other constants such as permitivity ε0, avogrado, N, and charge q. Homework Equations Utotal=-Nα(q2/4piε0)(1-ρ/R0) The Attempt at a Solution Tried to plug the values but I can't solve for R0 since...

Homework Statement I couldn't get the forces in equlibrium in this question Homework EquationsThe Attempt at a Solution VA + VD = 35(3.5) + 10+15 = 147.5 sum of moment about D = -35(3.5)(1.75+ 3.7) +15(1) + VA(3.5 + 1.7+ 2) = 0 VA = 90.6upwards Sum of moment about C = -35(3.5)(1.75+1.7)...

Homework Statement This is a three step problem (I am not fond of the multi-step problems as I can usually do better without multiple steps. Here is the problem: A uniform ring of mass m = 10 kg and radius r = 195 mm carries an eccentric mass m0 = 18 kg at a radius b = 160 mm and is in an...

I know the units of Kc are mol/liter. The units of Kp are either mol/atm or just atm. Not really sure. I get mles atm and liters in my answer when i solve. Pretty weird

Homework Statement Homework EquationsThe Attempt at a Solution I'm having trouble coming up with the equations for the system. At first, I thought that m2 = m1sin(theta), but that's not correct. How can I set this problem up?

Homework Statement In this experiment, a suspended metre-ruler lies in a series of equilibrium under non-parallel forces. Homework Equations The apparatus consists of the following. A metre rule suspended by strings which make an angle with the vertical. The strings run over pulleys which are...

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. a) Draw a free body diagram for the beam, clearly labelling all the forces acting on it b) Calculate the tension in the cable...

Homework Statement If the 4.4-kg block is suspended from the pulley B and the sag of the cord is d = 0.15 m, determine the force in cord ABC. Neglect the size of the pulley. (Figure 1) Express your answer to three significant figures and include the appropriate units.Homework EquationsThe...

Homework Statement As a stunt coordinator with a background in physics, you have been asked to determine whether Man can make it across the river and whether the rope will hold his weight. Man is rather small, with a mass of only about 48.7 kg, including his equipment. The crossing distance is...

If you were to look at a simple 2D or 3D static equilibrium diagram, where a mass is suspended by multiple ropes at different angles, my gut feeling is that there is a fairly simple proportion between the distance between the center of mass and the rope (the distance created opposite of the...

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...

This concept, though intuitive to some, appears to be counterintuitive for 20-80% of smart-to-brilliant students I teach. How can the idea of an object having non-zero speed while (balanced) forces act on that object, be conveyed without resorting to just a shuffling of physics terms to give a...

Homework Statement Homework Equations [/B] xcomponent of vector= magnitude*cosine of theta ycomponent of vector= magnitude*sine of theta Basic trig operations after this. Honestly I think that I am just having trouble with the algebra The Attempt at a Solution Because the magnitude of the...

Homework Statement Hello! I have a question about the following problem: Two point masses m1 and m2 are attached to isolating wires to point P. They are both positively charges (charge Q1 and Q2) and in the picture you can see the situation at equilibrium. What is the proportion of the...

Homework Statement A uniform bar with length c can slide a cylindrical surface with a radius of r. Determine the maximum angle theta that guarantees the equilibrium of the bar if the friction coefficient at the points of contact is u. Homework Equations Friction force = u*N (where N is the...

Homework Statement [/B] A door 1.00 m wide and 2.00 m high weighs 330 N and is supported by two hinges, one 0.50 m from the top and the other 0.50 m from the bottom. Each hinge supports half the total weight of the door. Assuming that the door’s center of gravity is at its center, find the...

Homework Statement question1-sentence https://www.physicsforums.com/attachments/105257 question1-answer https://www.physicsforums.com/attachments/105258 question2-sentence https://www.physicsforums.com/attachments/105259 question2-answer https://www.physicsforums.com/attachments/105260...

Homework Statement [/B] The following reaction was allowed to reach the state of equilibrium 2A+B <====> C The initial amounts of reactant present in one litre of solution were 0.5 mole of A and 0.6 mole of B. At equilibrium the amounts were 0.2 mole of A and 0.45 mole of B and 0.15 mole of...

Okay - a classic trap . multiplication times zero . I have a 3 foot bar weighing 10 lbs . its attached along its mid point to an axle . how much torque / force - do I need along its axle ( motorized ) to get it to spin 30 rpm or 60 rpm ? its in equilibrium , but of course it needs FORCE...

Homework Statement Assume that the pressure p in a star with spherical symmetry is related to the density \rho by the (distinctly unrealistic) equation of state p= \tfrac12 k\rho^2, where k is a constant. Use the fluid equilibrium equation obtained in Problem 23 to find a relation between \rho...

1. A uniform bar AB of length 3 m and weight 40 N rests in equilibrium with the lower end A on a smooth plane inclined at an angle alpha to the horizontal, where tan alpha = 3/4 and a point C of the rod against a smooth peg. If the rod makes an angle theta with the horizontal, where tan theta =...

1. A uniform right circular solid cone of weight W is suspended by two vertical strings attached to the ends A and B of a diameter of its base. If the cone hangs in equilibrium with its vertex vertically below A, find the tension in the strings. 2. Centre of mass of cone from the vertex is 3/4...

Homework Statement The portable reel is used to wind up and store an air hose. The tension in the hose is 100 N and a vertical 200-N force is applied to the handle in order to steady the reel frame. Determine the minimum force P which must be applied perpendicular to the handle DE and the...

Homework Statement Write an expression for Kc for the following at equilibrium; CaCO3(s) + CO2(g) + H2O(l) ⇔ Ca2+(aq) + 2HCO3-(aq) Homework Equations K = [products]^(coefficients)/[products]^(coefficients) The Attempt at a Solution I know that pure solid and liquid substances should be set...

3 forces, 5N,6N and 7N act on a particle which remains in a state of equilibrium. What is the angle between the 5N and 6N force?

The pressure of a liquid in equilibrium, is equal to the pressure of it's vapour, or to the sum of vapour pressure plus atmospheric pressure? My doubt starts from this problem: At 293 K and 1 atm, the vapour pressure of water is 565.8 Pa. Calculate the vapour pressure of water, when the total...

Homework Statement The two uniform rectangular plates each weighing 800 kg are freely hinged about their common edge and suspended by the central cable and four symmetrical corner cables. Calculate the tension T in each of the corner cables and the tension T0 in the center cable. All...

Equations: Net torque=0=Net force I believe this is a static equilibrium question but can't figure out how to do it

I've been trying to make an estimate for the pressure of the sun's photosphere using some sort of hydrostatic equilibrium equation, but I can't seem to get one that even comes close to agreeing with observations. Does anyone know what the right formula is and what the right way to approach the...

Homework Statement Determine [Zn2+], [CN–], and [HCN] in a saturated solution of Zn(CN)2 with a fixed pH of 1.060. The Ksp for Zn(CN)2 is 3.0 × 10–16. The Ka for HCN is 6.2 × 10–10. Homework Equations The Attempt at a Solution I don't have a phone or camera right now to take a picture of my...

Homework Statement Consider a rigid piston cylinder arrangement. Assume that the cylinder and the piston are covered by a perfectly insulating material and the piston cylinder interface is very smooth. Two types of ideal gases are separated in the cylinder by the piston. The number of gas...

Homework Statement Cu2+ ions react with Fe2+ ions according to the following reaction. Cu2+ + 2Fe2+ --> Cu + 2Fe3+ At equilibrium, the concentration of Cu2+ ions is not changed by the addition of A) Cu2++B) Fe2+C) CuD) Fe3+. Homework EquationsThe Attempt at a Solution I chose A through...

Hello. A known equation that is useful for calculating equilbrium constants is: ΔG° = -RT * ln(K) This is all well and good. Given a standard gibbs free energy of reaction for some given reaction, the equilibrium constant for the reaction can be found. My trouble is in which ΔG° to use. For...

Homework Statement Can an object be in equilibrium if it is in motion? Explain * This is a prelab question to a lab that deals with equilibrium and torque The attempt at a solution My thought process: - Equilibrium means that: 1) Net external forces = 0 2) Net torque = 0 - Net...

I mean, currently it seems that scientists are using equilibrium temperature of exoplanets (calculated assuming an Earth-like albedo) to determine whether a planet is habitable or not. But aren't there other more accurate ways to determine surface temperatures of exoplanets? I learned Wien's...

Homework Statement The attachment above contains the diagram given in the problem M1 = 25kg M2 = 35kg Friction coefficient between M1 and stucture = 0.15 Friction coefficient between M1 and M2 = 0.25 Friction on pulleys and mass on pulleys is negligible. Find the minimum mass M3 for sliding...

There is a stick of known length l and known mass m1 with its balance point in the middle. By placing an object of unknown mass m2 at the far end of the stick, the balance point moves towards the same end as the object by a distance of d. Calculate m2. Second, similar exercise: Stick of known...

In Principles of General Thermodynamics, Hatsopoulus and Keenan (p 442) make the following claim: What, however, would be some physical examples of such a system?

Homework Statement The plate has a dimension of 460mm X 260mm, subjected to a central load of 400N. Determine the reaction A and B, each representing a roller support as a wheel, located at the center of one edge. (opposite blue arrows have the same resultant value.) Are they the same ? If not...

Homework Statement A hot (800 K) iron nail of mass 150 g is placed into a 1.0 kg of water at 25°C. What is the common temperature of the 2 objects once they have reached thermal equilibrium? Assume no change of state of the water. Heat capacity of iron nail is 450 J/kg/K Heat capacity of...

Here's a random thought that I don't as yet have a satisfactory solution: Let's assume we have a copper column resting on an insulated table. Copper is an electric conductor, which means that some electrons within the copper column move freely throughout the column, subject to electromagnetic...

Homework Statement With which speed goes the Mass through the Equilibrium? Homework Equations Es = 1/2*D*s2 Ekin = 1/2*m*v2 Epot = m*g*h Energy in the zero point = below/ under highest Point: Epot = 1kg * 9,81N/kg*0.67m ≈ 6.573Nm Equilibrium : Ekin, Epot, Es Lowest Point: Es= 0 Ekin = 0...

Homework Statement For the system: \frac{dx}{dt}=x\cos{xy} \: \: \frac{dy}{dt}=-y\cos{xy} (a) is Hamiltonian with the function: H(x,y)=\sin{xy} (b) Sketch the level sets of H, and (c) sketch the phase portrait of the system. Include a description of all equilibrium points and any saddle...