# What is Equilibrium of forces: Definition and 22 Discussions

Thermodynamic equilibrium is an axiomatic concept of thermodynamics. It is an internal state of a single thermodynamic system, or a relation between several thermodynamic systems connected by more or less permeable or impermeable walls. In thermodynamic equilibrium there are no net macroscopic flows of matter or of energy, either within a system or between systems.
In a system that is in its own state of internal thermodynamic equilibrium, no macroscopic change occurs.
Systems in mutual thermodynamic equilibrium are simultaneously in mutual thermal, mechanical, chemical, and radiative equilibria. Systems can be in one kind of mutual equilibrium, though not in others. In thermodynamic equilibrium, all kinds of equilibrium hold at once and indefinitely, until disturbed by a thermodynamic operation. In a macroscopic equilibrium, perfectly or almost perfectly balanced microscopic exchanges occur; this is the physical explanation of the notion of macroscopic equilibrium.
A thermodynamic system in a state of internal thermodynamic equilibrium has a spatially uniform temperature. Its intensive properties, other than temperature, may be driven to spatial inhomogeneity by an unchanging long-range force field imposed on it by its surroundings.
In systems that are at a state of non-equilibrium there are, by contrast, net flows of matter or energy. If such changes can be triggered to occur in a system in which they are not already occurring, the system is said to be in a meta-stable equilibrium.
Though not a widely named "law," it is an axiom of thermodynamics that there exist states of thermodynamic equilibrium. The second law of thermodynamics states that when a body of material starts from an equilibrium state, in which, portions of it are held at different states by more or less permeable or impermeable partitions, and a thermodynamic operation removes or makes the partitions more permeable and it is isolated, then it spontaneously reaches its own, new state of internal thermodynamic equilibrium, and this is accompanied by an increase in the sum of the entropies of the portions.

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1. ### Potential barrier problem in mechanics

Here our sir said if I would apply energy conservation b/w initial point and B , we would get it wrong. But If I apply between initial point and D , we would get it right. He didn't tell why. Could anyone just explain why. One reason I thought was that since the question asked for minimum...
2. ### I Standard measure of distance from equilibrium for all systems

Is there a standard way to measure how far a system is displaced from equilibrium that can be applied to all physical systems? So, for example, a ball that is kicked, a spring that is stretched, a liquid that’s heated, and a charged battery are all systems that are displaced from equilibrium. I...
3. ### How do I solve this physics exercise (Equilibrium)?

I tried to solve it and I got the following, is it correct?
4. ### How to Calculate Tension Forces in a System?

Homework Statement Find the tension in each section of string in terms of ##θ_1##,m and g. Homework Equations Equilibrium of force,dimensional analysis of force. The Attempt at a Solution The support points are at rest and in each points,there are two equal tension force acting in opposite...
5. ### Finding Equilibrium of Forces: A Shortcut Method

Homework Statement The questions are in the comment box. Sorry! https://www.img.in.th/image/V9K8Rg Homework EquationsThe Attempt at a Solution 1. I think α = 90 because BD is normal force. and I don't know anymore PS. sorry for bad english
6. ### Equilibrium of forces (angle of road so car will not skid)

Hi everyone. Our mechanics professor warned us that in the mid-term exam some students reached the right answer on some questions but their method was wrong. For this reason sometimes I'm worried when I reach the correct answer but the way I did it is different from the solution guide. And I...
7. C

### Solving for the internal forces and reactions

Homework Statement I'm having a hard time finding the reactions at the supports and the force exerted by the spring. Given: 20 lbs 25 lbs 35 lbs k = 200 lb/ft lo = 2.5 ft members are 4 ft longHomework Equations ΣM ∑Fy = 0 ∑Fx = 0 The Attempt at a Solution I tried solving for the reactions...
8. ### Calculating tensions in ropes suspending an onject

Homework Statement A mass of 20 kg is suspended from a ceiling by two lengths of rope that make angles of 30° and 45° with the ceiling . Determine the tension in each of the strings. 2.Relevant equations Fg= mg The Attempt at a Solution Fg= 20 x 9.8 = 196 N ∑F= fnet=ma Fg-FTtotal= 0 196=...
9. ### How does friction act between PA and AB in an equilibrium of forces system?

Homework Statement The original question was to find the value of the angle between PA and AB. I have a certain idea regarding how to find it, but first I have to identify all forces acting on the system and their directions. So, I would be grateful if someone can explain how the frictional...
10. ### Statics: Equilibrium in 3-Dimensions

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...
11. ### Statics: Problem about Equilibrium in 3-dimensions

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...
12. ### Statics: Force Analysis of a Pipe Bender Machine

Homework Statement .The pipe bender consists of two grooved pulleys mounted and free to turn on a fixed frame. The pipe is bent into the shape shown by a force P=300N.Calculate the forces supported by the bearings of the pulleys.[/B] Homework Equations The force equilibrium equations in two...
13. ### How to find if equilibrium points of a force is un/stable?

Homework Statement U = Ax2 - Bx3 Homework Equations du/dx = 2Ax - 3Bx2 The Attempt at a Solution If I was given a potential energy function U = Ax2 - Bx3 and am asked to find: 1) The expression for the force as a function of x. 2) The equilibrium points and determine if are they stable or...
14. ### Solving Equilibrium Problem: Determine tan θ

Homework Statement The system is on static equilibrium. Determine tan θ ! Homework Equations ΣF = 0 Στ = 0 The Attempt at a Solution ∑Fx = 0 Ta sin θ = Tb ΣFy = 0 Ta cos θ = mg Then, I got stuck.. I want to continue to Στ = 0 but I don't know which one to pick as fulcrum, the...
15. ### Equilibrium of Forces Paradox

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...
16. ### Equilibrium of forces lab- Sources of error spring scale

I'm doing a lab where we use three strings connected to a ring, with each string attached to separate spring scales. What would be sources of error in this? And how does friction affect my results?
17. ### How Do You Calculate Tension in a Hanging Mirror?

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...
18. ### Equilibrium of Forces on the Table

Homework Statement This is a simple research problem that I am dealing with. It would be better to explain it with a diagram. There are three weights attached to some strings and tied together in a knot. There is an obstacle on the table. What happens to the weights under the situation...
19. ### Equilibrium of Forces in a Hemisphere: Solving for Angles and Ratios

Homework Statement A uniform thin straight bar AE is at rest inside a hemisphere in the configuration, under the assumption the friction between the bar and the hemisphere is negligible. This configuration is possible as long as the length of the bar remains within a limited range. The center...
20. ### Equilibrium of Forces on a Spring

Homework Statement A particle of mass M moves in one dimension along the positive x axis, under the influence of two forces. The first force is a constant force, with magnitude B and direction toward the origin. The second force is an inverse square law, with magnitude A/x2 and direction...
21. ### Equilibrium of forces acting at a point

1. can an object be moving and still be in equilibrium? 2. consider a ring with a pin in the center that's not connected to the ring. three weights are attached to the ring at different angles and are hanging from the side of the apparatus where the ring lies. what criteria will decide when the...
22. ### Equilibrium of Forces Acting on Point Mass: Cross Product with a

Three forces with magnitudes F_a, F_b, F_c act on a point mass, pulling in unit directions a, b, c, respectively. Thr forces are in 'equilibrium' which means that F_aa + F_bb + F_cc = 0 By taking the cross product with a, show that F_b(a \times b) = F_c(c \times a) and find two similar...