1. Matter and Energy

2. Drill Complete the following equations: 1) KE = 2) = m g h 3) = F d 4) Compression Work (isobaric) =

3. Matter and Energy Property – a characteristic used to describe a system State – a list of all the property values of a system Process– a record of all the states that a system passes through 12 3 45 6 State Process

4. Matter and Energy Energy can go into or out of a system as either work or heat …so far we’ve covered: Thermodynamics - “the study of systems and energy transfer” Work: Mechanical Work = F x d Expansion/Compression Work = Energy: Potential Energy (PE) = m g h Kinetic Energy (KE) = But what about the energy that is inside a substance?

5. Matter and Energy Internal Energy (U) = Thermodynamics - “the study of systems and energy transfer” The energy that is stored within a substance at the molecular or atomic scale due to its arrangements or movements The chemical energy that is stored within a substance such as in a battery Any nuclear energy that is stored within a substance + + Any energy associated with a substance that is not bulk kinetic or potential energy…

6. Matter and Energy Energy can go into or out of a system as either work or heat …so far we’ve covered: Thermodynamics - “the study of systems and energy transfer” Work: Mechanical Work = F x d Expansion/Compression Work = Energy, (E): Potential Energy (PE) = m g h Kinetic Energy (KE) = Internal Energy (U) Heat: Heat (Q) But how are these things all related? To answer that, we must introduce the 1 st Law of Thermodynamics } E = PE + KE + U

7. Matter and Energy 1 st Law of Thermodynamics: Thermodynamics - “the study of systems and energy transfer” “Energy can be neither created nor destroyed, only transformed.” “Any change in the energy of a closed system must be caused by either work or heat.” or…

8. Matter and Energy 1 st Law of Thermodynamics: Thermodynamics - “the study of systems and energy transfer” The subscripts “ 1-2 ” should be read as “ 1 to 2 ” and refer to a change in the state of the system from State 1 to State 2. State 1 State 2 Adding heat or work to a closed system changes the energy stored in the system; it changes the state of that system. What is the term that describes a change in the state of a system? Process

9. Matter and Energy 1 st Law of Thermodynamics: Thermodynamics - “the study of systems and energy transfer” This equation shows how work, heat and energy are related…it doesn’t determine the direction!!! Work and heat can enter or leave a system, and there is a sign convention that is used to show their direction.

10. Matter and Energy 1 st Law of Thermodynamics: Thermodynamics - “the study of systems and energy transfer” Sign Convention: Heat Transfer, (Q) Heat in is positive (+) Heat out is negative (-) Work, (W) Work in is negative (-) Work out is positive (+)

11. Matter and Energy 1 st Law example: Thermodynamics - “the study of systems and energy transfer” A piston cylinder containing a fluid is compressed while being cooled. If the work done is 5090 kJ and the heat removed is 1500 kJ, what is the change in energy of the fluid?