Chapter 11: Heat Chapter 12: Thermodynamics

Chapter 11: Heat Chapter 12: Thermodynamics Review Chapter 11 Heat heat a form of energy in transit SI unit is the joule (J) common nonstandard units are the kilocalorie (kcal) and the British thermal unit (BTU) mechanical equivalent of heat relates joules to kilocalories 1 kcal = 1000 calories = 1 Calorie = 4,186 J

Memorize this or write it on your blue sheet. heat energy work all have the same units; they are different forms of the same thing thermal conductivity the heat-conducting ability of a material H = Q = KA T t d On Gold Sheet where H is the thermal conductivity of the material

A is the cross-sectional area T is the temperature of the hot side of the conductor minus the temperature of the cold side of the conductor d is the thickness of the conductor ** On the gold sheet L is used to represent thickness. Chapter 12 Thermodynamics The ideal gas law is a thermodynamic equation of state. pV = nRT or pV = NkBT

On Gold Sheet where p is pressure in pascals (Pa) V is volume in cubic meters (m3) n is the number of moles R is the universal gas constant, 8.31 J/(molK) T is the temperature in kelvin N is the number of molecules kB is Boltzmanns constant, 1.38 x 10-23 J/K Know the vocabulary of thermodynamics. Know the 1st Law and sign conventions. The First Law of Thermodynamics is a statement of energy

conservation for thermodynamic systems. U = Q + W On Gold Sheet Q : heat U : change in internal energy W: work Sign Conventions The system is the gas, fluid, etc. you are analyzing. +Q means heat added to the system -Q means heat removed from the system

+W means work done on the system (compression) -W means work done by the system (expansion) isothermal constant temperature U = 0 ; Q = -W As U goes, so goes T. isobaric constant pressure W = - pV On Gold Sheet isometric constant volume W = 0; Q = U adiabatic no heat is exchanged Q = 0; U = W The area under the curve on a P-V graph is equal to work.

Internal energy is linked to temperature. Recall from Chapter 10, for ideal monatomic gases: U = 3/2 nRT or U = 3/2 NkBT The Second Law of Thermodynamics specifies the direction in which a process can naturally or spontaneously take place. Heat does not flow spontaneously from a colder to a warmer body. In a thermal cycle, heat energy cannot be completely transformed into mechanical work. The total entropy of the universe increases in every natural process. The Third Law of Thermodynamics It is not possible to lower

temperature to absolute zero, since it would violate the Second Law: no heat engine can be 100% efficient. heat engines convert heat to work For one cycle, the system returns to the same temperature and heat is converted to work done by the system. QH U = 0; Q = -W W QC thermal efficiency work out divided by work in e=

W Q On Gold Sheet thermal pump the reverse of a heat engine example: a refrigerator Coefficient of performance is a measure of efficiency for a thermal pump QH W QC

Carnot cycle the ideal heat engine give the upper limit of efficiency eC = TH TC TH On Gold Sheet entropy a measure of the disorder of a system The entropy of an isolated system increases for every natural process as well as all irreversible processes, such as free expansion. The entropy of an isolated system stays the same for all reversible processes and reversible cycles. Entropy of an isolated system never decreases. Entropy can only

decrease in a non-isolated system by doing work or expending energy. **Remember to use Kelvin for all thermodynamic formulas.

Recently Viewed Presentations

  • Welcome to... A Game of Xs and Os

    Welcome to... A Game of Xs and Os

    Title: No Slide Title Author: Mark E. Damon Last modified by: OIT machine2 Created Date: 3/18/2000 6:50:51 PM Document presentation format: On-screen Show
  • Te-8019

    Te-8019

    Department of Computer Engineering Fatih University Mobile and Pervasive Computing - 6 Projects for Groups Presented by: Dr. Adeel Akram University of Engineering and Technology, Taxila,Pakistan
  • Perianesthesia Emergencies

    Perianesthesia Emergencies

    Sepsis: (Fever and rigor) Blood cultures then antibiotics. New Onset Hypotension in PACU. Sign of: Drug overdose. Drug interactions. Hypovolemia. HYPOTENSION TREATMENT. Confirm accuracy of equipment. Fluid Replacement. Treat Dysrhythmias. Reverse anesthetics. Afterload Reduction.
  • KDE KEDS - Research Connections

    KDE KEDS - Research Connections

    On-screen Show (4:3) Other titles: Arial Cambria Calibri DejaVu Serif Wingdings Webdings KEDS Presentation KEDS2008 1_KEDS2008 2_KEDS2008 3_KEDS2008 4_KEDS2008 5_KEDS2008 6_KEDS2008 High Stakes Testing and Assessment: Quality and Children's Outcomes Slide 2 Why Develop an Assessment System?
  • Consumer Advocacy Program

    Consumer Advocacy Program

    The OIC's Consumer Advocacy Program. Answers consumer inquiries about insurance and their legal rights. Investigates complaints filed against insurance companies. Educates citizens to enable them to make informed choices about their insurance needs and options. February 3, 2017. Consumer Advocacy...
  • Chapter 21-Section 1-Taking on Segregation

    Chapter 21-Section 1-Taking on Segregation

    The Segregation System. The Civil Rights Act of 1875-Also referred to as the Enforcement Act or Force Act, guaranteed African Americans equal treatment in public accommodations, public transportation, and prohibited exclusion from jury service.. The Supreme Court ruled in 1883...
  • RVCF FALL 2016 CONFERENCE November 6-9, 2016 JW

    RVCF FALL 2016 CONFERENCE November 6-9, 2016 JW

    The discount chain issued a memo to more than 200 of its suppliers this week officially alerting them about a new policy, according to reports from several news agencies. Effective May 30, companies will be fined up to $10,000 for...
  • Psychology - PC\|MAC

    Psychology - PC\|MAC

    Dorothea Dix: reformer & activist, successfully pressured congress to construct & fund asylums for the mentally ill. Women currently account for ¾ of all Psychology Ph.D. graduates. Evolutionary Psychology. Breaks down the traditional barriers between sub-disciplines in psychology