![Page 1: Chapter19 Temperature , Heat , and the First Law of Thermodynamics](https://reader033.vdocuments.site/reader033/viewer/2022061618/56812cef550346895d91b887/html5/thumbnails/1.jpg)
Chapter19Chapter19
Temperature , Heat , and the Temperature , Heat , and the First Law of ThermodynamicsFirst Law of Thermodynamics
![Page 2: Chapter19 Temperature , Heat , and the First Law of Thermodynamics](https://reader033.vdocuments.site/reader033/viewer/2022061618/56812cef550346895d91b887/html5/thumbnails/2.jpg)
19-2 The Zeroth Law of Thermodynamics19-2 The Zeroth Law of Thermodynamics
If bodies A and B are each in thermal equilibrium with a third body T,then they are in thermal equilibrium with each other.
The zeroth law of thermodynamics:
![Page 3: Chapter19 Temperature , Heat , and the First Law of Thermodynamics](https://reader033.vdocuments.site/reader033/viewer/2022061618/56812cef550346895d91b887/html5/thumbnails/3.jpg)
19-3 Measuring Temperature19-3 Measuring TemperatureThe Triple Point of Water
erature)point temp-(triple 16.2733 KT
The Constant – Volume Gas Thermometer
CpT
ghpp 0
P is the pressure within the gas and C is a constant.
is the atmospheric pressure, is the density of the mercury in the manometer
33 CpT
is the gas pressure now
![Page 4: Chapter19 Temperature , Heat , and the First Law of Thermodynamics](https://reader033.vdocuments.site/reader033/viewer/2022061618/56812cef550346895d91b887/html5/thumbnails/4.jpg)
)lim)(16.273(3
0 p
pKT
gas
A temperature with a gas thermometer is
al)(provision ))(16.273()(33
3 p
pK
p
pTT
19-4 The Celsius and Fahrenheit Scales19-4 The Celsius and Fahrenheit Scales
00 95 FC
015.273TTC
0325
9 CF TT
FC 00 320
represents a Celsius temperature and T a Kelvin temperature
The relation between the Celsius and Fahrenheit scales is
![Page 5: Chapter19 Temperature , Heat , and the First Law of Thermodynamics](https://reader033.vdocuments.site/reader033/viewer/2022061618/56812cef550346895d91b887/html5/thumbnails/5.jpg)
Sample Problem 19-1Sample Problem 19-1
FFFT 1591910.32
ZZZ 0.84)0.98(0.14
F
Z
FZ 191
0.79
180)0.84(
19-5 Thermal Expansion19-5 Thermal Expansion
![Page 6: Chapter19 Temperature , Heat , and the First Law of Thermodynamics](https://reader033.vdocuments.site/reader033/viewer/2022061618/56812cef550346895d91b887/html5/thumbnails/6.jpg)
Linear ExpansionTLL
is a constant called the coefficient of linear expansion.
Volume ExpansionTVV
3Is the coefficient of volume expansion of the solid or liquid.
Sample Problem 19-2Sample Problem 19-2
L
LL
VVVdel
36190
80837000
L
KCL
TVV
808
)0.23)(/1050.9)(37000( 4
![Page 7: Chapter19 Temperature , Heat , and the First Law of Thermodynamics](https://reader033.vdocuments.site/reader033/viewer/2022061618/56812cef550346895d91b887/html5/thumbnails/7.jpg)
19-6 Temperature and Heat19-6 Temperature and Heat
Heat is the energy that is transferred between a system and its environment because of a temperature difference that exists between them.
JBtucal 1860.410969.31 3
Definition of heat:
![Page 8: Chapter19 Temperature , Heat , and the First Law of Thermodynamics](https://reader033.vdocuments.site/reader033/viewer/2022061618/56812cef550346895d91b887/html5/thumbnails/8.jpg)
19-7 The Absorption of Heat by 19-7 The Absorption of Heat by Solids and LiquidsSolids and Liquids
Heat Capacity)( if TTCTCQ
and are the initial and final temperatures of the object.
Specific Heat)( if TTcmTcmQ
KkgJFbBtuCgcalc /41901/1/1
Molar Specific Heatunits elementary 106.02 mol 1 23
![Page 9: Chapter19 Temperature , Heat , and the First Law of Thermodynamics](https://reader033.vdocuments.site/reader033/viewer/2022061618/56812cef550346895d91b887/html5/thumbnails/9.jpg)
Heats of TransformationThe amount of energy per unit mass that must be transferred as heat when a sample completely undergoes a phase change is called the heat of transformation L.
LmQ
The heat of vaporization
kgkJmolkJgcalLV /2256/7.40/539
kgkJmolkJgcalLF /333/01.6/5.79
The heat of fusion
![Page 10: Chapter19 Temperature , Heat , and the First Law of Thermodynamics](https://reader033.vdocuments.site/reader033/viewer/2022061618/56812cef550346895d91b887/html5/thumbnails/10.jpg)
Sample Problem 19-3Sample Problem 19-3(a)
Step 1kJJ
CCkgKkgJ
TTmcQ ifice
98.1515984
)]10(0)[720.0)(/2220(
)(1
kJJ
CCkgKkgJ
TTmcQ ifliq
25.4545252
)015)(720.0)(/4190(
)(3
kJkgkgkJmLQ F 8.239)720.0)(/333(2
kJ
kJkJkJ
QQQQtot
300
25.458.23998.15321
gkgkgkJ
kJ
L
Qm
F
rem 580583.0/333
194
Step 2
Step 3
(b)
ggg 140580720
![Page 11: Chapter19 Temperature , Heat , and the First Law of Thermodynamics](https://reader033.vdocuments.site/reader033/viewer/2022061618/56812cef550346895d91b887/html5/thumbnails/11.jpg)
Sample Problem 19-4Sample Problem 19-4
For the water:For the beaker:
For the copper:
)( ifwww TTmcQ
)( TTmcQ fccc
)( ifbb TTCQ
0 cbw QQQ0)()()( TTmcTTCTTmc fccifbifww
ccbww
iwwibccf mcCmc
TmcTCTmcT
![Page 12: Chapter19 Temperature , Heat , and the First Law of Thermodynamics](https://reader033.vdocuments.site/reader033/viewer/2022061618/56812cef550346895d91b887/html5/thumbnails/12.jpg)
19-8 A Closer Look at Heat and Work19-8 A Closer Look at Heat and WorkThe differential work dW done by the gas during the displacement is
f
i
V
VpdVdWW
pdVAdspdspAsdFdW
)())((
The gas to change its volume from Vi to Vf ,the total work done by the gas is
![Page 13: Chapter19 Temperature , Heat , and the First Law of Thermodynamics](https://reader033.vdocuments.site/reader033/viewer/2022061618/56812cef550346895d91b887/html5/thumbnails/13.jpg)
There are actually many ways to take the gas from state i to state f .
![Page 14: Chapter19 Temperature , Heat , and the First Law of Thermodynamics](https://reader033.vdocuments.site/reader033/viewer/2022061618/56812cef550346895d91b887/html5/thumbnails/14.jpg)
19-9 The First Law of Thermodynamics19-9 The First Law of Thermodynamics
The first law of thermodynamics:law)(first int,int,int WQEEE if
law)(first int dWdQdE
The internal energy Eint of a system tends to increase if energy is added as heat Q and tends to decrease if energy is lost as work W done by the system.
![Page 15: Chapter19 Temperature , Heat , and the First Law of Thermodynamics](https://reader033.vdocuments.site/reader033/viewer/2022061618/56812cef550346895d91b887/html5/thumbnails/15.jpg)
19-10 Some Special Cases of the 19-10 Some Special Cases of the First Law of ThermodynamicsFirst Law of Thermodynamics
The Law:
Process Restriction Consequence
Adiabatic Q=0 =-W
Constant volume W=0 =Q
Closed cycle =0 Q=W
Free expansion Q=W=0 =0
1.Adiabatic processes.
2. Constant - volume
3.Cyclical processes.
4.Free expansions.
WQ WE int
QE int0int E
![Page 16: Chapter19 Temperature , Heat , and the First Law of Thermodynamics](https://reader033.vdocuments.site/reader033/viewer/2022061618/56812cef550346895d91b887/html5/thumbnails/16.jpg)
Sample Problem 19-5Sample Problem 19-5
(a)
MJkJ
kJkJWQE
09.22090
1692256int
JJ
mmPa
VVpdVppdVW if
V
V
V
V
f
i
f
i
1691069.1
)1000.1671.1)(1001.1(
)(
5
3335
kJkJ
kgkgkJmLQ V
22602256
00.1)(/2256(
(b
)
(c)
![Page 17: Chapter19 Temperature , Heat , and the First Law of Thermodynamics](https://reader033.vdocuments.site/reader033/viewer/2022061618/56812cef550346895d91b887/html5/thumbnails/17.jpg)
19-11 Heat Transfer Mechanisms19-11 Heat Transfer MechanismsConduction
L
TTkA
t
QP CH
cond
The conduction rate
Thermal Resistance to Conduction (R-Value)
k
LR
Conduction Through a Composite Slab
1
1
2
2 )()(
L
TTAk
L
TTAkP CXXH
cond
![Page 18: Chapter19 Temperature , Heat , and the First Law of Thermodynamics](https://reader033.vdocuments.site/reader033/viewer/2022061618/56812cef550346895d91b887/html5/thumbnails/18.jpg)
1221
1221
LkLk
TLkTLkT HC
X
)/(
)(
kL
TTAp CH
cond
2211 //
)(
kLkL
TTAp CH
cond
Radiation
)( 44 TTAPPP envradabsnet
4ATPrad
4envabs ATP
![Page 19: Chapter19 Temperature , Heat , and the First Law of Thermodynamics](https://reader033.vdocuments.site/reader033/viewer/2022061618/56812cef550346895d91b887/html5/thumbnails/19.jpg)
Sample Problem 19-6Sample Problem 19-6
ddd
aaa L
TTAkP
L
TTAkP 5421 and
5214 )( TTTLk
LkT
ad
da
C
CCCLk
LkT
aa
aa
0.8
)10()2025()0.5(
)0.2(4
Sample Problem 19-7Sample Problem 19-7
t
EPrad
)()()( 41
42
41
42
1212
TTAttATtAT
tPtPEEE rr
![Page 20: Chapter19 Temperature , Heat , and the First Law of Thermodynamics](https://reader033.vdocuments.site/reader033/viewer/2022061618/56812cef550346895d91b887/html5/thumbnails/20.jpg)
232 10027.5)020.0(4 mmA
JKKs
mKmWE
8.406])308()320)[(1200(
)10027.5)(80.0)(/106703.5(44
23428
JJE
81.0500
8.406
500
KCCT 320273472
KCCT 308273351
![Page 21: Chapter19 Temperature , Heat , and the First Law of Thermodynamics](https://reader033.vdocuments.site/reader033/viewer/2022061618/56812cef550346895d91b887/html5/thumbnails/21.jpg)
REVIEW & SUMMARYREVIEW & SUMMARYThe Kelvin Temperature Scale
)lim)(16.273(3
0 p
pKT
gas
A temperature with a gas thermometer is
Celsius and Fahrenheit Scales
015.273TTC
0325
9 CF TT
represents a Celsius temperature and T a Kelvin temperature
The relation between the Celsius and Fahrenheit scales is
![Page 22: Chapter19 Temperature , Heat , and the First Law of Thermodynamics](https://reader033.vdocuments.site/reader033/viewer/2022061618/56812cef550346895d91b887/html5/thumbnails/22.jpg)
Thermal ExpansionTLL
is a constant called the coefficient of linear expansion.
TVV
3Is the coefficient of volume expansion of the solid or liquid.
HeatJBtucal 1860.410969.31 3
Heat Capacity and Specific Heat)( if TTCTCQ
and are the initial and final temperatures of the object.
![Page 23: Chapter19 Temperature , Heat , and the First Law of Thermodynamics](https://reader033.vdocuments.site/reader033/viewer/2022061618/56812cef550346895d91b887/html5/thumbnails/23.jpg)
)( if TTcmTcmQ
Where c is the specific heat of the material making up the object.
Heat of Transformation
LmQ
Work Associated with Volume Change
f
i
V
VpdVdWW
The gas to change its volume from Vi to Vf ,the total work done by the gas is
First Law of ThermodynamicsThe first law of thermodynamics:
law)(first int,int,int WQEEE if
![Page 24: Chapter19 Temperature , Heat , and the First Law of Thermodynamics](https://reader033.vdocuments.site/reader033/viewer/2022061618/56812cef550346895d91b887/html5/thumbnails/24.jpg)
Applications of the First Law1.Adiabatic processes.
2. Constant - volume
3.Cyclical processes.
4.Free expansions.
WQE , 0intWEQ int , 0
QEW int , 0 0int EWQ
law)(first int dWdQdE
Conduction , Convection , and Radiation
L
TTkA
t
QP CH
cond
The conduction rate
4ATPrad 4
envabs ATP