important terms notes n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Important Terms & Notes PowerPoint Presentation
Download Presentation
Important Terms & Notes

Loading in 2 Seconds...

play fullscreen
1 / 21

Important Terms & Notes - PowerPoint PPT Presentation


  • 85 Views
  • Uploaded on

Important Terms & Notes. Conceptual Physics Mar. 17, 2014. Entropy. A measure of the amount of disorder in a system. Δ S = Δ Q/T. Entropy. The idea of ordered energy tending to disordered energy? What is Ordered or Organized Energy? Energy that can be transformed or used to perform work

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Important Terms & Notes' - neith


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
important terms notes

Important Terms & Notes

Conceptual Physics

Mar. 17, 2014

entropy
Entropy
  • A measure of the amount of disorder in a system.

ΔS = Δ Q/T

entropy1
Entropy
  • The idea of ordered energy tending to disordered energy?
  • What is Ordered or Organized Energy?
  • Energy that can be transformed or used to perform work
  • What is Disordered energy?
  • Energy that has been transformed into a non-usable form (“Waste Energy”).
entropy2
Entropy
  • Natural Systems tend to proceed toward a state of greater disorder.
  • Examples:
  • The Universe after the BIG BANG.
  • Organic decomposition: Food Rotting
  • Ice cube Melting
  • Dye into a glass of water.
  • One’s Messy Room??
entropy3
Entropy
  • Increasing or Decreasing, Reversible or irreversible:
  • Liquid water becoming Ice Cubes? Under what circumstances?
  • A log Burning?
  • Pushing a heavy block across the floor?
  • Air Molecules being blown into a balloon?
  • Air Molecules escaping out of a balloon?
entropy4
Entropy
  • How does one reverse Entropy???
  • Can one Reverse Entropy??
first law of thermodynamics
First Law of Thermodynamics
  • Heat added to a system is transformed into an equal amount of some other form of energy.
  • A version of the Law of Energy Conversion

ΔQ = ΔEi + W

second law of thermodynamics
Second Law of Thermodynamics
  • Heat will never of itself flow from one object to another of higher temperature.
  • Heat will not flow from Cold to Hot without work being performed.
the laws of thermodynamics
The Laws of Thermodynamics
  • You CAN’T Win
    • because you can not get any more Energy out of a system than you put in
  • You CAN’T Break even
    • because you can even get the same amount of Energy out of a system that you put in
  • You CAN’T Get Out of the Game
    • Because entropy in the Universe is always increasing
adiabatic
Adiabatic
  • The term applied to the expansion or compression of a gas occurring without the gain or loss of heat.
  • Example: Activity within the Cylinders of an Internal Combustion Engine
heat engine
Heat Engine

A Device that Changes Internal Energy into Mechanical Energy

the heat engine
The Heat Engine

Carnot engine diagram (modern) - where heat flows from a high temperature TH furnace through the fluid of the "working body" (working substance) and into the cold sink TC, thus forcing the working substance to do mechanical workW on the surroundings, via cycles of contractions and expansions.

carnot efficiency
Carnot Efficiency
  • The Ideal maximum percentage of input energy that can be converted into work in a heat engine.
  • Ideal Efficiency = (Thot – Tcold)/Thot
chapter 24 review questions questions 1 8
Chapter 24 Review QuestionsQuestions 1 - 8
  • Greek meaning: Movement of Heat
  • Thermodynamics is concerned with Macroscopic processes.
  • Lowest possible temperatures:

a. On Kelvin scale : 0° K

b. On Celsius Scale: -273° C

  • Temperature of Melting Ice on the

Absolute Scale: +273 ° K

chapter 24 review questions questions 1 8 cont
Chapter 24 Review QuestionsQuestions 1 -8 (cont.)
  • Temperature of Boiling Water on the

Absolute Scale: +373 ° K

  • Energy cannot be created nor destroyed;

therefore , Energy (Heat) added to a system

can only change to an equal amount of

another form of energy.

ΔQ = ΔE +W

chapter 24 review questions questions 1 8 cont1
Chapter 24 Review QuestionsQuestions 1 -8 (cont.)

6. Work done on a system should result in an increase of the

Internal Energy of that System.

The temperature of that system should increase as well since

the average kinetic energy of the system has increased.

7. ΔQ = ΔEi + W

8. Work done on a system should result in an increase in the

Internal Energy of that System.

Work done by a system should result in an decrease in the

Internal Energy of that System.

chapter 24 review questions questions 9 16
Chapter 24 Review QuestionsQuestions 9 - 16

9. No Heat is gained or Lost by the System.

10a. The Air temperature increases during

adiabatic compression.

10b. The Air temperature decreases during

adiabatic expansion.

11. The temperature of rising air generally

cools as it rises.

chapter 24 review questions questions 9 16 cont
Chapter 24 Review QuestionsQuestions 9 - 16 (cont.)

12. The temperature of falling air generally

increases as it rises.

13. Since heat , of itself, will only flow from hot to cold, in order to force heat to flow from cold to hot work MUST be performed.

14. Three processes occurring in every heat engine

High Temperature, Low temperature,

Work Done

chapter 24 review questions questions 9 16 cont1
Chapter 24 Review QuestionsQuestions 9 - 16 (cont.)

15. Thermal Pollution is the undesirable heat expulsion from a process.

16.No. According to the Carnot Efficiency (which is based on the temperature difference between processes) a Heat Engine cannot achieve 100% efficiency even if the effects of friction are removed.

Ideal Efficiency = (Thot – Tcold)/Thot

chapter 24 review questions questions 17 25 cont
Chapter 24 Review QuestionsQuestions17 - 25 (cont.)
  • Eff= (Thot – Tcold)/Thotin KELVINS: 40%
  • To Increase efficiency
  • Organized Energy: Electricity used to heat a room, A car breaking to stop…WHY???
  • 100% we perceive some of that energy transformation as light.
  • Natural Systems: Tend to Disorder. Disordered state will tend to order only when work is applied
chapter 24 review questions questions 17 25 cont1
Chapter 24 Review QuestionsQuestions 17 - 25 (cont.)

22. Messy Physicist: Dr. Entropy

23. Decrease in Entropy: With organized Energy input or work done on the system.

24. Entropy increases in natural systems.

25. 1st Law: No exceptions

2nd Law: Exceptions may occur under proper

circumstances.