University:
Eastern Kentucky University
Course:
PHY 131 | College Physics I
Academic year:

2020
Views:

347

Pages:

1
Author:

Marilyn James

Physics and Math 3: Thermodynamics 0th Law of Thermodynamics Thermal Equilibrium: When systems have the same average KE and thus the same temperature. No heat transfer. Temperature: The average kinetic energy of the particles that make up a substance. % ℉=($ $℃$)+32 & ℃= & % $(℉−32) 𝐾 = $℃+273 Thermal Expansion: Describes how a substance changes in length or volume as a function of the change in temperature. D𝐿=$a$𝐿$D𝑇 1st Law of Thermodynamics A statement of conservation of energy: The total energy in the universe can never decrease or increase. For an individual system: ∆𝑈 = 𝑄 −𝑊 ∆𝑈=change$in$systemA s$internal$energy 𝑄 =energy$transferred$into$the$system$as$heat 𝑊 =work$done$by$the$system Heat: The process by which energy transfer between two objects at different temperatures that occurs until the two objects come into thermal equilibrium (reach the same temperature). 𝑞 =𝑚$𝑐$D𝑇 Specific Heat: The amount of energy necessary to raise one gram of a substance by 1° C or 1 K. MNO Specific heat of H2O = 1P$•$Q = 4.184 R P$•$Q D𝑉=$b$𝑉$D𝑇 Systems Isolated System: Do not exchange matter or energy with surroundings. Closed System: Exchange energy but not matter with their surroundings. Open System: Exchange both energy and matter with their surroundings. Heat of The energy required for a phase change of a substance Transformation: (temperature does not change during the transformation). 𝑞 =𝑚$𝐿 L = heat of transformation Processes with Isobaric: Pressure is constant, DP = 0 Constant Variable: Isothermal: Temp is constant, DU = 0 Adiabatic: No heat is exchanged, Q = 0 Isovolumetric (isochoric): Volume is constant, DV = 0, so Work = 0 Work of a Gas: 𝑊 =−𝑃$∆𝑉 State Functions: Pathway independent and are not themselves defined by a process. Include: Pressure, density, temp, volume, enthalpy, internal energy, Gibbs free energy, and entropy. Process Describe the pathway from one equilibrium state to Functions: another. Include: work and heat. 2nd Law of Thermodynamics In a closed system, up to and including the universe, energy will spontaneously and irreversibly go from being localized to being spread out. Note: An isolated system does not exchange energy or matter with surroundings Entropy: A measure of how much energy has spread out or how spread out energy has become.