Equilibrium Definition and 1000 Threads

Homework Statement Two supports, made of the same material and initially of equal length, are 2.0m apart. A stiff board with a length of 4.0m and a mass of 10 kg is placed on the supports, with one support at the left end and the other at the midpoint. A block is placed on the board a...

A long straight metal rod has a radius of 5 cm and a charge per unit length of 30 nC/m. Find the electric field x cm away where distance is perpendicular to the rod.The solution to this uses ## \int E\cdot dA = \dfrac{q_{encl}}{\epsilon_0}##. My question is, why can you use this? I thought...

Homework Statement A uniform ladder is 10 m long and weighs 180 N. In the figure below, the ladder leans against a vertical, frictionless wall at height h = 8.0 m above the ground. A horizontal force is applied to the ladder at a distance 1.0 m from its base (measured along the ladder). (a)...

Homework Statement Estimate the value of the equilibrium constant at 670K for the following reaction: 2NO2(g)⇌N2O4(g)Homework Equations ΔG°rxn = -RT*lnKThe Attempt at a Solution This should be an easy problem. But for some reason, MasteringChem won't accept it, so I'm wondering if I did...

Homework Statement Charges 4q and -q are located at the points (-2a,0,0) and (-a,0,0), respectively. Write down the potential θ(x,y) for points in the xy plane, and then use a Taylor expansion to find an approximate expression for θ near the origin, which you can quickly show is the...

Unfortunately there's no link to the test. This is from the test administered a month ago. Homework Statement A choppah is flying horizontally at constant speed. A perfectly flexible uniform cable is suspended beneath the choppah; air friction on the cable is NOT negligible. Which of...

Homework Statement Rxn: 2SO2 (g) + O2 (g) \Leftrightarrow 2SO3 (g) If the initial concentration of SO3 is .500 M (moles/liter) @1500K, what are the final concentrations of [SO2], [O2] and [SO3]. Kc = .15 Stop when you get to the cubic equation Homework Equations RICE table...

I'm currently studying for a test and I'm having problem with this concept: If I have 3 different Equilibrium constants for different reactions like Kc=103, Kc=1 and KC=10-4, which one's forward reaction is most favorable, and which one's reverse reaction is most favorable? Maybe it's the...

What formula (if there is one) would you use for a rod that is in equilibrium where there are n number of forces acting on the rod in either of the two perpedicular directions to the length of the rod, where each force is different, and where each force is acting at a different point along the...

Homework Statement A ball of mass M = 0.320kg is connected by a light but rigid rod of length L = 0.770m to a pivot and held in place with the rod being vertical. A wind exerts a constant force F to the right on the ball. The ball is released from rest, and the wind makes it swing up to a...

Homework Statement 0.05625 m^3 of H2O(s) is added to a thermally isolated system of 20 L of H2O (l). If the ice was initially at 0 C and the liquid water was initially at 95 C, what is the final state and temperature? The Attempt at a Solution I missed class for this so I'm going by...

I can't finish the last problems on my homework. I asked my teacher and he wouldn't help me, can someone please help me? I'm so confused!

Homework Statement Calculate the force P that is required to hold the 120lb roller at rest on the rough incline. (see attachments for Free body diagram)Homework Equations Summation of Forces X = 0 Summation of Forces Y = 0 Summation of Moment along A = 0 Moment = Fd The Attempt at a Solution...

Homework Statement Three masses are disposed in a circular lane and linked with springs (resting lengths Lo). Find the potential energy and, from it, the equilibrium positions. (see image: https://www.dropbox.com/s/evqcspwlj68p5n9/2014-02-05%2016.07.07.jpg ) Homework Equations The...

[b]1. An electron is placed between two charged parallel plates. The electron is in equilibrium between the electric force and the gravitational force. a) Make a drawing of the experimental setup. Label the direction of the gravitational field, the placement of the plates, and indicate which...

Homework Statement A 3.6-kg block of ice originally at 263 K is placed in thermal contact with a 13-kg block of silver (cAg = 233 J/kg-K) which is initially at 1006 K. The H2O and silver system is insulated from any other heat transfer. 1)At what temperature will the system achieve...

Two Blocks Connected by Pulley System Homework Statement [EDIT] sorry, I forgot to post the goal of this problem. [EDIT] I wrote the question wrong. At what point does the system come to rest? What is the maximum distance it will fall? Two blocks are connected by a rope and pulley system...

A 3.0-kg ball and a 1.0-kg ball are placed at opposite ends of a massless beam so that the system is in equilibrium as shown. Note: The drawing is not drawn to scale. What is the ratio of the lengths, b/a? (a) 2.0 (c) 3.0 (e) 5.0 (b) 2.5 (d) 4.0

Help -- Confusion acid-base equilibrium in water Hello, I have been reading about the acid-base equilibrium in water. I don't understand what my book explains however. The theory may be information lacking(in my opinion). Because I've read it so many times I just decided to rewrite everything...

Homework Statement Suppose 337g of water at 32.9°C is poured over a 59.3g cube of ice with a temperature of -5.67°C. Does all the ice melt? If all the ice melts, what is the final temperature of the water? If all of the ice does not melt, how much ice remains when the ice-water mixture reaches...

1. A horizontal, 10-m plank weighs 100 N. It rests on two supports that are placed 1.o m from each end. How close to one end can an 800-N person stand without causing the plank to tip?

So I was watching a video about Gibbs-Donnan equilibrium () On one side of the semipermeable membrane, there is a solution of potassium ions and impermeable protein ion (negative 1 charge). On the other side there is potassium chloride. It said that after the electrical and chemical...

Mass 1 is located at the far left end of a 90 cm beam. Mass 2 is located at the center of the beam, and mass 3 is located 30 cm from the center, on the right side. Mass 3 and mass 1 are the same. If the fulcrum is located 10 cm to the left of the center of the beam, what is the mass of mass 2 if...

I have read that in electrostatic equilibrium, their are no electric fields or else the charges would be moving. So given a positively charged spherical shell, the positive charges would repel each other and reside on the outside, causing the shell to be in electrostatic equilibrium. But if...

In Chemistry, if a substance is in equilibrium between its vapour and liquid, does it account for the dissolved gas molecules? I have always heard that the rate of evaporate = rate of condensation in a case like this, but does the rate of evaporation include the dissolved gases escaping and...

Homework Statement A)A ladder of weight 80N rests against a smooth wall at an angle of 29 degrees to the vertical with its end on a rough horizontal floor.If the ladder is in equillibrium calculate the reaction (magnitude and direction) of the ground and the wall. Bi)a man of weight 80N...

Homework Statement The given force F is equal to 5000N,γ=〖30〗^o and α=〖15〗^o. The moment on member 4 is to be found. The geometry of the structure was worked out separately. Homework Equations To solve the problem I tried to use the Equilibrium equations which state that...

a man is trying to fix the light bulb at the top of his house ceiling.to reach the bulb,he is using a stepladder that is in equilibrium state.sides AC and CE are each 9.0 m long and hinged at C.Bar BD is attached with a rod that is 3.0 m long,halfway up.The man who is climbing 5.0 m along the...

Is there a relationship between increasing temperature in one test tube and keeping the other temperature constant and the time it takes to reach thermal equilibrium Homework Statement Is there are relationship between increasing the temperature of water and keeping the other same and the...

Why are the reactions from two objects not at equilibrium ?

Using this graph: http://postimg.org/image/vkv0ho8yb/ As the reaction proceeds it stops at the equilibrium as it has the lowest Gibbs energy. However, I don't understand why ΔG=0 at that point. As shown in the arrow isn't the ΔG greater in magnitude than when the reaction goes to completion...

The person in the system above has a mass of 60 kg. If the system is in equilibrium, what is the coefficient of friction between the person and the ground, to two decimal places? I need help on this question , I have done some work on it which is given below: Converted masses into...

Homework Statement Given force F (=5000N), find Moment on member 4. I have attempted to start solving this problem by drawing the following diagram: I added the letter 'A' to the support of member 2, and also put an angle of 7 degrees to the vertical at the support 1. I have...

I was hoping someone could lend a hand with a question about thermodynamics. It's been years since I've done work on thermodynamics. Let's say I have a plastic 275 gallon liquid container, filled with a mixture of Propylene Glycol and Water (50/50 by volume). The container is placed inside of...

Homework Statement A mass,M, is fixed at a position of 3m. Another mass, 2M, is fixed at the position -1m. What position(s) can a third mass, 3M, be placed so that it is in equilibrium. Homework Equations The only thing I could think of is M(3)+2M(-1)+3Mx=0 The Attempt at a...

Homework Statement Nitrous oxide reacts with ozone to form dinitrogen pentoxide. There are four moles of each reactant and the volume of the container in which this reaction takes place is 2 L. T is constant. The equilibrium constant for this reaction is 1. How many moles of product are...

Homework Statement Two solid steel shafts are coupled together using meshed gears. Determine the angle of twist of end A. Shaft DC is fixed at D. Homework Equations angle of twist = torque * shaft length / ( polar moment of inertia * shear modulus) balance of forces where the two gears...

Homework Statement Suppose we have a mixture of the gases H2, CO2, CO and, H2O at 1200 K, with partial pressures pH2 = 0.55 bar, pCO2 = 0.2 bar, pCO = 1.25 bar, and pH2O = 0.1 bar. Is the reaction described by the equation CO + H2O <=> H2 + CO2 at equilibrium under these conditions? If not...

I wonder if there's a physics person here who could help me solve this problem. the loads applied to the truss shown in the figure cause reactions shown at A & D. A free body diagram of hinge A forms concurrent force system shown enclosed at A. Determine the magnitude of forces P & F directed...

Homework Statement A uniform sphere of weight mg and radius r0 is tethered to a wall by a rope of length ℓ. The rope is tied to the wall a distance h above the contact point of the sphere, as shown in the figure.(Figure 1) The rope makes an angle θ with respect to the wall and is not in line...

Homework Statement The top view of a table, with weight Wt, is shown in the figure. (Figure 1) The table has lost the leg at (Lx, Ly), in the upper right corner of the diagram, and is in danger of tipping over. Company is about to arrive, so the host tries to stabilize the table by placing a...

If we know that the Polarization P in LIH dielectrics is proportional to the net field inside the dielectric according to: P = ε0χeE...(1) And we know that D = εE...(2) Does it not follow that we can ascertain the polarization directly from the applied (free charge) field, since we...

I am a little confused with this subject. If you have a mass hanging from a spring, there is a specific equilibrium point, but what if you apply a force downwards on the mass, will this have an effect on the equilibrium position or will it remain the same? thanks!

Homework Statement http://postimg.org/image/scm11r483/ So when considering the free body diagram for member BE, why is the force P not included? Does the Ex account for the bit of the P=210 that would act on member BE?

Hie guys, Two cords can each support a maximum load of 100 N,we need to find the maximum weight of crate that can be hoisted at contant velocity. My question is which cord am i suppose to consider as 100N?

Homework Statement uk of fraction between bar and both surfaces is 0.2. Bar weighs 5 kg. i) Is the bar in static equilibrium? If not, which end will fall down and which end will go up? Homework Equations F-uk*FnThe Attempt at a Solution Not sure how to even begin analyzing this. I cannot...

Homework Statement Homework Equations How to do this question ?? The Attempt at a Solution I know sum of torque and force = 0 at fapplied i got torque = 25sin(45) * 3.8m = 67.18N .. But don't know what to do next !

Homework Statement Ends A and B of the 5-kg rigid bar are attached by lightweight collars that may slide over the smooth fixed rods shown in the figure. The center of mass of the bar is at its midpoint. The length of the bar is 1.5 m. Determine the horizontal force F applied to...

Homework Statement In the diagram below, masses m and Me are in circular orbit about Ms with the same period. http://min.us/i/lprtU83D9cGR Derive an expression for the equilibrium position r of mass m. Homework Equations For a circular orbit, the eccentricity, e = 0...

I determined the equilibrium point of a spring by setting the potential energy function U(r) equal to zero and solving for r. But I just looked at the guided solution, and they took the derivative of U(r) first, then solved for r. Is my approach correct? Can we solve for the equilibrium...