Six Ideas that Shaped Physics: Unit T: Some Processes are Irreversible

204 Pages·2·162.372 MB·\204

by  Thomas Moore

Some Physical Constants
Standard Metric Prefixes
Speed of light c 3.00 x 108 m/s For powers of 10
Gravitational constant G 6.67 x 10~n N m2/kg;
Power Prefix Symbol
Coulomb's constant k 8.99 x 109 N m2/C2
Planck's constant h 6.63 x 10-34 J s 1018 exa E
1015 peta P
Boltzmann's constant kB 1.38 x 10-23 J/K 1012 tera T
Elementary charge e 1.60 x 10-19C 110099 giga G
Electron mass me 9.11 x IO-31 kg 110066 mega M
Proton mass mp 1.67 x 10~27 kg 103 kilo k
Neutron mass m„ 1.68 x 10~27 kg 10"2 centi c
10-3 milli m
10"6 micro
Commonly Used Physical Data 10-9 nano n
1100--1122 pico
Gravitational field strength g 9.80 J kg-1 m"1 = 9.80 m/s2 1100--1155 femto fP
Mass of the earth Me 5.98 x 1024 kg 10-18 atto a
Radius of the earth R
e 6380 km (equatorial)
Mass of the sun M
s 1.99 x 1030 kg
Radius of the sun Rs 696,000 km
Distance to moon 3.84 x 108 m
Distance to sun
1.50 x 10u m
Density of water+
1000.0 kg/m3 = 1 g/cm3
Density, of air+
1.2 kg/m3
Absolute zero
0 K = —273.15°C = —459.67°F
Freezing point of water* 273.15 K = 0°C = 32°F
Room temperature 295 K - 22°C = 72°F
Boiling point of water* 373 K = 100°C = 212°F
Normal atmospheric pressure
101.3 kPa
Useful Conversion Factors
1 meter — 1 m = 100 cm = 39.4 in. = 3.28 ft
1 m/s = 2.24 mi/h
1 mile = 1 mi = 1609 m = 1.609 km = 5280 ft
1 mi/h = 1.61 km/h
1 inch = 1 in. = 2.54 cm
1 ft3 = 0.02832 m3
1 light-year = 1 ly = 9.46 p 0.946 x 1016 m
m =
1 hour = 1 h = 60 min = 3600 s 1 gallon = 1 gal = 3.79 x 10"3 m3 « 3.8 kg H20
1 N = 1 kg m/s2 = 1 J/m = 0.225 lb
1 day = 1 d = 24 h = 86.4 ks = 86,400 s
1 lb = 4.45 N
1 year = 1 y 365.25 d = 31.6 Ms = 3.16 x 107«
=
Weight of 1-kg object near earth = 9.8 N = 2.2 lb
1J = 1 kg m2/s21 N • m = 0.239 cal
1 cal = energy to raise temperature of 1 g of H 0 by 1 K
leal = 4.186 J 2
1 food calorie = 1 Cal = 1 kcal = 1000 cal
1W = 1 J/
s
1 horsepower = 1 hp = 746 W
1 kW • h =3.6 MJ
1 Pa = 1 N/m2
1 K (temperature difference) = 1°C = 1 8°F /5°C\
C] = { ¥ f ){ tw ~ 3 2°F)
T=(d|) fT[C]+273.15°C] (5K\
T = (^gTp J +459.67°F)
1 rad = 57.3° = 0.1592 rev
1 rev — 360° = 2j: radians = 6.28 rad
At normal pressure, 20°C
*A t normal atmospheric pressure.
Specific Heats of Various Materials5
Substance
Specific Heat (J kq~1 K~
Elemental Solids:
Lead
128
Gold
129
Silver
234
Copper
387
Iron
448
Aluminum
900
Other Solids:
Granite
760
Glass
837
Marble
860
Wood
1700
Ice (-10°C)
2200
Liquids:
Mercury
139
Ethyl Alcohol
2430
Water
4186
Air
« 740
3d edSUpe530 300 K Unl6SS 0therwise noted- Based on Serwa7' ^ysics,
Latent Heats of Various Substances11
At Standard Pressure
Latent Heat of
Substance Melting Point (K) Vaporization
(kJ/kq)
Helium
(does not solidify at 1 atm)
Hydrogen 14.0 4.2 21
58.6
Oxygen 54.8 20.3 452
13.8
Nitrogen 63.2 90.2 213
25.5
Mercury 234 77.4 201
11.3
Water 273 630 296
333
Lead 601 373 2256
24.7
Aluminum 933 2013 853
105
Copper 1356 2720 11,400
205
2840 4730
'
.
\ '
•
• .
a
Mc
Graw
~3>
Boston Burr Ridge, IL Dubuque, IA Madison, Wl New York San Francisco St. Louis
d Bangkok Bogota Caracas Kuala Lumpur Lisbon London Madrid Mexico City
Milan Montreal New Delhi Santiago Seoul Singapore Sydney Taipei Toronto
O
McGraw-Hill Higher Education gg
A Division of The McGraw-Hill Companies
SIX IDEAS THAT SHAPED PHYSICS, UNIT T: SOME PROCESSES ARE IRREVERSIBLE
SECOND EDITION
Published by McGraw-Hill, a business unit of The McGraw-Hill Companies, Inc., 1221
Avenue of the Americas, New York, NY 10020. Copyright © 2003,1998 by The McGraw-Hill
Companies, Inc. All rights reserved. No part of this publication may be reproduced or
distributed in any form or by any means, or stored in a database or retrieval system, without
the prior written consent of The McGraw-Hill Companies, Inc., including, but not limited to,
in any network or other electronic storage or transmission, or broadcast for distance learning.
Some ancillaries, including electronic and print components, may not be available to
customers outside the United States.
This book is printed on recycled, acid-free paper containing 10% postconsumer waste.
4 5 6 7 8 9 0 QPD/QPD0 9 8 7
ISBN 978-0-07-239715^
MHID 0-07-239715-2
Publisher: Kent A. Peterson
Sponsoring editor: Daryl Bruflodt
Developmental editor: Spencer J. Cotkin, Ph.D
Marketing manager: Debra B. Hash
Senior project manager: Susan ]. Brusch
Senior production supervisor: Sandy Ludovissy
Coordinator of freelance design: David W. Hash
Cover/interior designer: Rokusek Design
Cover image: ©Nova Development
Senior photo research coordinator: Lori Hancock
Photo research: Chris Hammond/PhotoFind LLC
Supplement producer: Brenda A. Ernzen
Media project manager: Sandra M. Schnee
Media technology associate producer: Judi David
Compositor: Interactive Composition Corporation
Typeface: 10/12 Palatino
Printer: Quebecor World Dubuque, IA
Credit List:
Chapter 1 T1.6: © Frozen Images/Image Works. Chapter 2 T2.5: © Corbis/Vol. 1; T2.6: NASA.
Chapter 3 T3.10: © National Center For Atmospheric Research/University Corporation for
Atmospheric Research/National Science Foundation; Pg. 56(right): © Vivian Peevers/Peter
Arnold. Chapter 5 T5.7: © McGraw-Hill Companies, Inc., photo by C. P. Hammond;
T5.8: © Peter Vandermark/Stock Boston; Pg. 91: April 1997 cover, © 1997 by Scientific
American, Inc. All rights reserved. Chapter 6 Page 110: Courtesy of NRAO/AUI. Chapter 7
Page 132: © Karen Su/Stock Boston. Chapter 8 T8.3,T8.5: © Richard Megna/Fundamental
Photographs. Chapter 9 T9.4: Courtesy Niagara Mohawk; T9.5 © by John Wiley & Sons.
Used by permission of John Wiley & Sons, Inc.; T9.6: National Oceanic and Atmospheric
Administration/Department of Commerce; T9.8: Courtesy of Lennox Industries Inc.;
T9.15: Courtesy of Leybold Didactic, GMBH.
Library of Congress Cataloging-in-Publication Data
Moore, Thomas A. (Thomas Andrew)
Six ideas that shaped physics. Unit T, Some processes are irreversible / Thomas A.
Moore. — 2nd ed.
p. cm.
Includes index.
ISBN 0-07-239715-2 (acid-free paper)
1. Irreversible processes. I. Title.
QC318.17.M66 2003
536.7—dc21 2001056201
CIP
www.mhhe.com
Dedication
For Allison,
whose warmth is legendary.

Table of Contents for
Six Ideas That Shaped Physics
Unit C Unit R
Conservation Laws Constrain The Laws of Physics Are
Interactions Frame-Independent
CI Introduction to Interactions R1 The Principle of Relativity
C2 Vectors R2 Synchronizing Clocks
C3 Interactions Transfer Momentum R3 The Nature of Time
C4 Particles and Systems R4 The Metric Equation
C5 Applying Momentum Conservation R5 Proper Time
C6 Introduction to Energy R6 Coordinate Transformations
C7 Some Potential Energy Functions R7 Lorentz Contraction
C8 Force and Energy R8 The Cosmic Speed Limit
C9 Rotational Energy R9 Four-Momentum
CIO Thermal Energy RIO Conservation of Four-Momentum
Cll Energy in Bonds
C12 Power, Collisions, and Impacts
C13 Angular Momentum Unit E
C14 Conservation of Angular Momentum
Electric and Magnetic Fields
Are Unified
El Basic Electrostatics
Unit N
E2 Electric Fields
The Laws of Physics Are Universal E3 Electrostatic Potential
E4 Conductors
N1 Newton's Laws
E5 Driving Currents
N2 Vector Calculus
E6 Analyzing Circuits
N3 Forces from Motion
E7 Magnetic Fields
N4 Motion from Forces
E8 Magnets and Currents
N5 Statics
E9 Symmetry and Flux
N6 Linearly Constrained Motion E10 Gauss' Law
N7 Coupled Objects
Ell Ampere's Law
N8 Circularly Constrained Motion
E12 The Electromagnetic Field
N9 Noninertial Reference Frames
E13 Maxwell's Equations
N10 Projectile Motion
E14 Induction
Nil Oscillatory Motion
E15 Waves
N12 Introduction to Orbits
E16 Electromagnetic Waves
N13 Planetary Motion
VIII
Table of Contents for Six Ideas That Shaped Physics
Unit Q
Q14 Radioactivity
Particles Behave Like Waves
Q15 Nuclear Technology
Q1 Standing Waves
Q2 The Wave Nature of Light
Unit T
Q3 The Particle Nature of Light
Q4 The Wave Nature of Matter Some Processes Are Irreversible
Q5 The Quantum Facts of Life
Q6 The Wavefunction T1 Temperature
Q7 Bound Systems T2 Ideal Gases
Q8 Spectra T3 Gas Processes
Q9 Understanding Atoms T4 Macrostates and Microstates
Q10 The Schrodinger Equation T5 The Second Law
Qll Energy Eigenfunctions T6 Temperature and Entropy
Q12 Introduction to Nuclei T7 Some Mysteries Resolved
Q13 Stable and Unstable Nuclei T8 Calculating Entropy Changes
Heat Engines
Contents: Unit T
Some Processes Are Irreversible
About the Author
XI T3.5: Computing the Work 46
Preface T3.6: Adiabatic Processes 50
XIII
Two-Minute Problems 53
Introduction for Students
XVI Homework Problems 54
Answers to Exercises 57
Chapter T1
Temperature
Chapter T4
Chapter Overview
Macrostates and Microstates 58
Tl.l Introduction to the Unit
T1.2 Irreversible Processes 4 Chapter Overview 58
T1.3 The Paradigmatic Thermal Process 7 T4.1 Distinguishing Macrostates from Microstates 60
T1.4 Temperature and Equilibrium 8 T4.2 The Einstein Model of a Solid 61
T1.5 Thermometers 9 T4.3 Counting Microstates 63
T1.6 Temperature and Thermal Energy 14 T4.4 Two Einstein Solids in Thermal Contact 66
Two-Minute Problems 15 T4.5 The Fundamental Assumption 67
Homework Problems 16 T4.6 Using StatMech 68
Answers to Exercises 19 Two-Minute Problems 71
Homework Problems 72
Answers to Exercises 74
Chapter T2
Ideal Gases
20
Chapter T5
Chapter Overview 20
T2.1 A Microscopic Model of an Ideal Gas 22 The Second Law 76
T2.2 Temperature and Energy 26 Chapter Overview 76
T2.3 Molecular Speeds and Brownian Motion 28 T5.1 What Happens as Systems Become Large? 78
T2.4 The Thermal Energy of a Gas 30 T5.2 Irreversibility in Einstein Solids 79
T2.5 Solids and Liquids 32 T5.3 Irreversibility in General 84
T2.6 Conclusions 33 T5.4 The Definition of Entropy 85
Two-Minute Problems 34 T5.5 The Second Law of Thermodynamics 87
Homework Problems 34 T5.6 Entropy and Disorder 88
Answers to Exercises 37 Two-Minute Problems 90
Homework Problems 91
Answers to Exercises 93
Chapter T3
Gas Processes 38
Chapter T6
Chapter Overview 38
T3.1 Review of Heat and Work 40 Temperature and Entropy 94
T3.2 Work During Expansion or Compression 42 Chapter Overview 94
T3.3 The State of a Gas 44 T6.1: The Definition of Temperature 96
T3.4 P-V Diagrams and Constrained Processes 45 T6.2: Consistency with the Old Definition 98