© 2010 Pearson Education, Inc. PowerPoint ® Lectures for College Physics: A Strategic Approach, Second Edition Chapter 11 Using Energy

© 2010 Pearson Education, Inc. Slide 11-3

© 2010 Pearson Education, Inc. Slide 11-4

© 2010 Pearson Education, Inc. Slide 11-5

© 2010 Pearson Education, Inc. Efficiency Slide 11-13

© 2010 Pearson Education, Inc. Reading Quiz 1.A machine uses 1000 J of electric energy to raise a heavy mass, increasing its potential energy by 300 J. What is the efficiency of this process? A.100% B.85% C.70% D.35% E.30% Slide 11-6

© 2010 Pearson Education, Inc. Answer 1.A machine uses 1000 J of electric energy to raise a heavy mass, increasing its potential energy by 300 J. What is the efficiency of this process? A.100% B.85% C.70% D.35% E.30% Slide 11-7

© 2010 Pearson Education, Inc. Example Problem Light bulbs are rated by the power that they consume, not the light that they emit. A 100 W incandescent bulb emits approximately 4 W of visible light. What is the efficiency of the bulb? Slide 11-12

© 2010 Pearson Education, Inc. The Ideal Gas Model Slide 11-18

© 2010 Pearson Education, Inc. Rank the following temperatures, from highest to lowest. A.300 °C > 300 K > 300 °F B.300 K > 300 °C > 300 °F C.300 °F > 300 °C > 300 K D.300 °C > 300 °F > 300 K Checking Understanding:Temperature Scales Slide 11-19

© 2010 Pearson Education, Inc. Rank the following temperatures, from highest to lowest. A.300 °C > 300 K > 300 °F B.300 K > 300 °C > 300 °F C.300 °F > 300 °C > 300 K D.300 °C > 300 °F > 300 K Answer Slide 11-20

© 2010 Pearson Education, Inc.  What is Heat??  Energy transferred between 2 objects at different temperatures.  Always flows from hot to cold  Zeroth Law of Thermodynamics:

© 2010 Pearson Education, Inc.  How to increase the thermal (internal) energy of the water?

© 2010 Pearson Education, Inc. Slide  U = W + Q

© 2010 Pearson Education, Inc.  First Law of Thermodynamics   U = Q + W  +Q…heat flows into system  -Q…heat flows out of system  +W…Work done ON System  -W…Work done BY system

© 2010 Pearson Education, Inc. Operation of a Heat Engine Slide 11-26

© 2010 Pearson Education, Inc. The Theoretical Maximum Efficiency of a Heat Engine Slide 11-27

© 2010 Pearson Education, Inc. Operation of a Heat Pump Slide 11-29

© 2010 Pearson Education, Inc. Second Law of Thermodynamics Slide 11-34

© 2010 Pearson Education, Inc. Summary Slide 11-37

© 2010 Pearson Education, Inc. Summary Slide 11-38