Equilibrium

What is Equilibrium?

Equilibrium is the state at which opposing forces are balanced. The force as well as torque both equal zero. The forces don't always have to be equal as shown int eh picture below but they do have to be equal. An object can be moving and still have a state of equilibrium as long the center of mass is moving at a constant velocity.

Torque:

"A torque is an influence which tends to change the rotational motion of an object."
Torque is a measure of how much force is acting on an object that causes the object to rotate. In this picture, the force is going down on the radius (lever) at a point that is called the pivot point. The torque will rotate around the pivot point.

One equation of torque is =Fr

This is like one of the problems we did in class. We had the force and the radius and we just multiplied them together to find the torque of the wrench.

Some Types of Equilibrium:

Hyperbolic Equlibrium

Physics Equilibrium:

• Equilibrant Force: considered to be the equal and opposite of the resultant force
• Equilibrium Mode Distribution: a state in which power is distributed to all modes equally
• Hydrostatic Equilibrium: the pressure at any point in a fluid is at rest is due to the weight of the overlying fluid
• Hyperbolic Equilibrium Point: a fixed point that does not have any chambers branching into openings.
• Mechanical Equilibrium: a state where there is no physical change. It is known a s a state of steadiness
• Radiative Equilibrium: the temperature of an object is constant with the time
• Secular Equilibrium: a situation when the quantity of a radioactive isotope remains constant. This is because the production rate is equal to the rate of decay

Chemistry Equilibrium:

• Thermodynamic Equilibrium: when two objects are in thermodynamic equilibrium with a third object, hey are in equilibrium with each other. "It is observed that some property of an object, like the press in a volume of gas, the length of a metal rod, or the electrical conductivity of a wire, can change when the object is heated or cooled. If two f these objects are brought into physical contact there is initially a change in property of both objects. But eventually, the change in property stops and the objects are said to be in thermodynamic equilibrium."
• Chemical Equilibrium: there is a constant ratio between the products and the concentration of reactants.
• Diffusive Equilibrium: state at which the concentrations of diffusing substances in two compartments become equal to each other.
• Thermal Equilibrium: state where one object has a higher temperature than the other one. When they become closer to having the same temperature, they become a state of thermal equilibrium.
• Donnan Equilibrium: the equilibrium of small ions between a solution with charged macromolecules and one without.
• Dynamic Equilibrium: when the rate of a forward reaction is equal to the rate of a backward reaction
• Equilibrium Constant: the constant is usually expressed in a form of "k". It is the relationship between reactants and the products of a reaction.
• Partition Equilibrium: this is a special id of chemical equilibrium because it is equilibrium of different substances at different phases.
• Quasistatic Equilibrium: a thermodynamic process that happens slow enough so that the system can remain in internal equilibrium 
• Schlenk Equilibrium: a chemical equilibrium that takes place in solutions of Grignard reagents 2 RMgX MgX₂ + MgR₂.
• Solubility Equilibrium: " Solubility equilibrium is based on the assumption that solids dissolve in water to give the basic particles from which they are formed"
• Vapor-liquid Equilibrium: VLE is a condition in which a liquid an dits vapor are in equilibrium with each other. The rate of evaporation is equal to the rate of condensation.

  

  Vapor Liquid Equilibrium

Biology Equilibrium

• Equilibrioception: sense of balance in a physiological sense
  
• Equilibrium Unfolding:the process of unfolding a protein or RNA molecule by changing its environment. For example, changing the temperature or applying some sort of force.
• Genetic Equilibrium: a condition where the alleles do not change from generation to generation
• Homeostasis: "the property of a system in which variables are regulated so that internal conditions remain stable and relatively constant."
• Punctuated Equilibrium: a theory that suggests that a species has been stable and most likely shows very little change for most of its history
• Sedimentation Equilibrium: "it is an analytical ultracentrifugation method for measuring protein molecular masses in solution and for studying protein to protein interactions."

Along with these equilibriums, there are examples of equilibriums in economics as well as game theory.

States of Equilibrium:

• Neutral Equilibrium: a kind of equilibrium so that with a small or insignificant change, it still
  
  remains in a state of equilibrium. An example of this is a sphere rolling on a flat surface. If it is stopped at any point, it will be in equilibrium.
• Unstable Equilibrium: a kind of equilibrium so that when the object is slightly changed, it go further from its original position.
• Stable Equilibrium: a kind of equilibrium so that with a small change, forces emerge which help return the object back into a state of equilibrium. An example of this is when the center of gravity is below the point of support. 
• Static Equilibrium: a kind so that when the system is at equilibrium, the forces will equal zero. When, the forces acting on the object are at rest, they are in a state of static equilibrium. An example is 
  
  In this picture, 
       A is neutral equilibrium
       B is stable equilibrium
       C is unstable equlibrium

Equilibrium in the Human Body:

Equilibrium in the human body allows for humans to stand up straight and allows them to walk. Equilibrioception also relates to the human body because it is the balance of a humans physiological sense. A huge part of this a humans center of gravity. If their is more mass to one side of their body, the human must compensate for it or they will fall over. As shown in the picture, each center of gravity or mass is different because of the way their body is and what they are carrying.

Bibliography:

http://chemwiki.ucdavis.edu/Core/Physical_Chemistry/Equilibria/Chemical_Equilibria/The_Equilibrium_Constanthttp://hyperphysics.phy-astr.gsu.edu/hbase/thermo/thereq.htmlhttp://www.academia.edu/568899/General_Equilibrium_Theory_its_history_and_its_relation_if_any_to_the_Market_Economyhttp://en.fphysics.com/states_of_equilibriumhttps://isaacphysics.org/concepts/cp_equilibriumhttps://www.shodor.org/unchem/advanced/equ/http://www.merriam-webster.com/dictionary/unstable%20equilibriumhttps://www.khanacademy.org/science/chemistry/chemical-equilibriumhttps://www.khanacademy.org/search?search_again=1&page_search_query=equilibriumhttp://www.thefreedictionary.com/Unstable+equilibriumhttp://www-rohan.sdsu.edu/~aty/explain/thermal/hydrostatic.htmlhttps://www.grc.nasa.gov/www/k-12/airplane/thermo0.htmlhttp://dev.physicslab.org/document.aspx?doctype=3&filename=dynamics_staticequilibrium.xmlhttps://www.chem.tamu.edu/class/majors/tutorialnotefiles/ksp.htmhttp://apollo.lsc.vsc.edu/classes/met130/notes/chapter2/rad_equil.htmlhttp://www.britannica.com/science/equilibrium-physics
http://hyperphysics.phy-astr.gsu.edu/hbase/torq.html
https://www.physics.uoguelph.ca/tutorials/torque/Q.torque.intro.html