science

• Thermodynamics


  The study of energy and its interaction with matter
• Thermodynamics


  • It specifically refers to heat and its transformation to mechanical energy
  • It covers macroscopic properties such as work, pressure, and temperature, and their involvement in energy transformations
  • It deals with the changes in the system using the properties that can be measured and observed in experiments
• Thermodynamic system


  A definite macroscopic region in the universe where thermodynamic processes take place
• Surroundings


  Everything outside the system and interacts with it
• Boundary


  The fixed border that separates the system and the surroundings
• Open system


  • Allows the exchange between both matter and energy with the surroundings
  • Heat is also freely exchanged with the surroundings
• Open system


  • Water being heated in a pan
• Closed system


  Allows the exchange of energy but not matter with the surroundings
• Closed system


  • Covered pan with boiling water inside
• Isolated system


  Does not allow exchange of both matter and energy with the surroundings
• Isolated system


  • Hot water placed in a thermos bottle
• Internal energy


  The total energy within a system, abbreviated as U
• Substances such as water and copper of the same mass and temperature have different internal energies
• Zeroth Law of Thermodynamics


  • Essential in defining the concept of thermal equilibrium and temperature scales
  • "If two systems are each in thermal equilibrium with a third, they are also in thermal equilibrium with each other"
• First Law of Thermodynamics


  • A restatement of the law of conservation of energy which states that energy cannot be created nor destroyed but can change into other forms
  • The change in internal energy can be achieved by adding heat to the system and by doing work on it
• The heat input in a simple steam engine is used to increase the temperature of the system as well as to do work on the piston
• Mechanical work, such as stirring, can increase the temperature of the system
• Isobaric process


  The pressure remains constant even if the gas expands or compresses
• Adiabatic process


  There is no energy which enters or leaves the system
• Isochoric or isovolumetric process

  There is no change in the volume, therefore, there is also no work done or by the system
• Isothermal process


  • The temperature of the system remains constant
  • The work done on the system is equal to the negative value of the thermal energy transferred to the system
• Thermodynamic processes


  • Isobaric, adiabatic, isochoric, isothermal
• An ideal gas releases 1.35 × 10^3 J of heat and does 3.45 × 10^3 J of work. What is the change in the internal energy of the gas?
• Second Law of Thermodynamics


  Heat flows spontaneously from a substance with a higher temperature to a lower temperature and does not flow spontaneously in the other direction
• Heat naturally flows from a hotter object to a colder one
• Entropy


  • A measure of the disorder in a system
  • Natural processes go in a direction that maintains or increases the total entropy of the universe
  • All usable, high-quality energy turn into less useful energy
• A certain metal melted at 200°C, accompanied by a change in entropy of 90.3 J/K. Find the heat associated with the phase change.
• Third Law of Thermodynamics


  • It gives the lowest temperature that can be achieved by a system (absolute zero or 0 K or -273.15°C)
  • It states that the entropy of a perfect crystal is zero when the temperature of the crystal is equal to absolute zero
• Thermodynamics is the study of heat - the transformation it undergoes and the way it interacts with matter
• In thermodynamics, we only focus on the processes occurring in the system rather than the surroundings
• Zeroth law of thermodynamics

  If two systems are in thermal equilibrium with a third, then they are also in thermal equilibrium with each other
• First law of thermodynamics


  The change in internal energy of a system is equal to the heat added to the object plus the work done on the object
• Third law of thermodynamics

  The entropy of a perfect crystal is zero when the temperature of the crystal is equal to absolute zero
• Terms being described


  • Lowest temperature that can be achieved by a system
  • Measure of the disorder in a system
  • Heat flows spontaneously from a substance with higher temperature to a lower temperature and does not flow spontaneously in the other direction
  • Thermodynamics process wherein there is no energy which enters or leaves the system
  • Total energy within a substance
• Faughn, Jerry S. and Raymond A. Serway. 2006. Serway's College Physics, 7th Edition. Singapore: Brooks/Cole.
• Gardose-Figueras, Geraldine. 2009. Science Fundamentals for High School IV: Physics. Philippines: Trinitas Publishing Inc.
• Hewitt, Paul G. 2002. Conceptual Physics, 9th Edition. Singapore: Pearson Education.
• Young, Hugh D., Roger A. Freedman, and A. Lewis Ford. 2009. University Physics, 12th Edition. Singapore: Pearson Education.
• Zitzewitz, Paul W.,David G. Haase and Kathleen A. Harper. 2013. Physics: Principles and Problems. United States: Glencoe/McGraw-Hill.