Download - material. • To use temperature as a measure of hotness and … · 2020-04-08 · K. Heat and Temperature 1. Temperature & Thermal Equilibrium Thermometer • First, select any measurable

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Page 1: material. • To use temperature as a measure of hotness and … · 2020-04-08 · K. Heat and Temperature 1. Temperature & Thermal Equilibrium Thermometer • First, select any measurable

K. H

eat

an

d T

em

pera

ture

Ch

ap

ter

Ou

tlin

e

1.

Tem

pera

ture

and T

herm

al E

quili

brium

2.

Therm

om

ete

rs a

nd T

em

pera

ture

Scale

s

3.

Therm

al E

xpansio

n

4.

Quantity

of H

eat

�2

01

0 H

erb

ert

B. D

om

ing

o

5.

Calo

rim

etr

yand P

hase C

hanges

K. H

eat

an

d T

em

pera

ture

1. T

em

pe

ratu

re &

Th

erm

al

Eq

uil

ibri

um

•C

on

ce

pt o

f te

mp

era

ture

ro

ote

d in

q

ua

lita

tive

id

ea

s o

f “h

ot”

an

d “

co

ld”

ba

se

d o

n s

en

se

of

tou

ch

.

•M

an

y p

rop

ert

ies o

f m

atte

r w

e c

an

m

ea

su

re d

ep

en

d o

n te

mp

era

ture

.

•T

em

pe

ratu

re is a

lso

re

late

d to

�2

01

0 H

erb

ert

B. D

om

ing

o

•T

em

pe

ratu

re is a

lso

re

late

d to

kin

etic e

ne

rgie

so

f m

ole

cu

les o

f m

ate

ria

l.

•T

o u

se

te

mp

era

ture

as a

me

asu

re

of h

otn

ess a

nd

co

ldn

ess, w

e n

ee

d

to c

on

str

uct

a t

em

pe

ratu

re s

ca

le.

Page 2: material. • To use temperature as a measure of hotness and … · 2020-04-08 · K. Heat and Temperature 1. Temperature & Thermal Equilibrium Thermometer • First, select any measurable

K. H

eat

an

d T

em

pera

ture

1. T

em

pe

ratu

re &

Th

erm

al

Eq

uil

ibri

um

Th

erm

om

ete

r

•F

irst,

se

lect a

ny m

ea

su

rab

le p

rop

ert

y o

f a

syste

m

tha

t va

rie

s w

ith

its

“h

otn

ess”

an

d “

co

ldn

ess”.

•E

xa

mp

les: th

e le

ng

th o

f a

liq

uid

(m

erc

ury

, e

tha

no

l)

in a

tu

be

, p

ressu

re o

f g

as a

nd

th

e e

lectr

ica

l

�2

01

0 H

erb

ert

B. D

om

ing

o

in a

tu

be

, p

ressu

re o

f g

as a

nd

th

e e

lectr

ica

l

resis

tan

ce

of

a

co

nd

uctin

g w

ire

.

•E

ach

of th

e a

bo

ve

ca

n

be

use

d t

o m

ake

a th

erm

om

ete

r.

K. H

eat

an

d T

em

pera

ture

1. T

em

pe

ratu

re &

Th

erm

al

Eq

uil

ibri

um

Th

erm

al E

qu

ilib

riu

m

•W

e u

se

a t

he

rmo

me

ter

to m

ea

su

re t

he

te

mp

era

ture

of a

bo

dy.

•A

t th

e p

oin

t w

he

re t

he

re

ad

ing

on

th

e t

em

pe

ratu

re

rea

ch

es a

ste

ad

y v

alu

e, th

e c

on

ditio

n o

f th

erm

al

�2

01

0 H

erb

ert

B. D

om

ing

o

rea

ch

es a

ste

ad

y v

alu

e, th

e c

on

ditio

n o

f th

erm

al

eq

uili

bri

um

ha

s o

ccu

rre

d.

Insu

lato

r

•A

n in

su

lato

r re

du

ce

sth

e e

xch

an

ge

of

he

at

be

twe

en

tw

o s

yste

ms.

•E

xa

mp

les o

f in

su

lato

rs: w

oo

d,

pla

stic fo

am

, o

r

fib

erg

lass.

Page 3: material. • To use temperature as a measure of hotness and … · 2020-04-08 · K. Heat and Temperature 1. Temperature & Thermal Equilibrium Thermometer • First, select any measurable

K. H

eat

an

d T

em

pera

ture

1. T

em

pe

ratu

re &

Th

erm

al

Eq

uil

ibri

um

Insu

lato

r

•A

n id

ea

l in

su

lato

ris

a m

ate

ria

l th

at

pe

rmits n

o

inte

ractio

n a

t a

ll b

etw

ee

n t

wo

syste

ms, th

us

pre

ve

ntin

g th

erm

al e

qu

ilib

riu

m f

rom

be

ing

re

ach

ed

.

Ze

roth

La

w o

f T

he

rmo

dyn

am

ics

�2

01

0 H

erb

ert

B. D

om

ing

o

Ze

roth

La

w o

f T

he

rmo

dyn

am

ics

•It

is a

n im

po

rta

nt

pro

pe

rty

of th

erm

al e

qu

ilib

riu

m

•C

on

sid

er

thre

e s

yste

ms:

A,

Ba

nd

C.

K. H

eat

an

d T

em

pera

ture

1. T

em

pe

ratu

re &

Th

erm

al

Eq

uil

ibri

um

Ze

roth

La

w o

f T

he

rmo

dyn

am

ics

•S

yste

m A

an

d B

initia

lly s

ep

ara

ted

by id

ea

l

insu

latin

g w

all,

bu

t w

e le

t C

inte

ract w

ith

Aa

nd

B.

•T

he

id

ea

l in

su

latin

g w

all

is th

en

pla

ce

d b

etw

ee

n C

an

d A

an

d B

an

d a

co

nd

uctin

g w

all

is p

lace

d

�2

01

0 H

erb

ert

B. D

om

ing

o

an

d A

an

d B

an

d a

co

nd

uctin

g w

all

is p

lace

d

be

twe

en

Aa

nd

Bto

le

t th

em

in

tera

ct.

•E

xp

eri

me

nt

sh

ow

s t

ha

t n

oth

ing

ha

pp

en

s!

•T

ha

t is

, th

ere

is n

o a

dd

itio

na

l ch

an

ge

s t

o A

an

d B

.

•C

on

clu

sio

n:

If C

is in

itia

lly in

th

erm

al e

qu

ilib

riu

m

with

bo

th A

an

d B

, th

en

Aa

nd

Ba

re a

lso

in

th

erm

al

eq

uili

bri

um

with

ea

ch

oth

er.

Page 4: material. • To use temperature as a measure of hotness and … · 2020-04-08 · K. Heat and Temperature 1. Temperature & Thermal Equilibrium Thermometer • First, select any measurable

K. H

eat

an

d T

em

pera

ture

1. T

em

pe

ratu

re &

Th

erm

al

Eq

uil

ibri

um

Ze

roth

La

w o

f T

he

rmo

dyn

am

ics

•S

up

po

se

we

re

pla

ce

Cw

ith

a t

he

rmo

me

ter

an

d is in

co

nta

ct w

ith

Aa

nd

B.

•W

he

n th

erm

om

ete

r re

ach

es a

sta

ble

va

lue

, b

oth

A

an

d B

ha

s t

he

sa

me

te

mp

era

ture

.

�2

01

0 H

erb

ert

B. D

om

ing

o

an

d B

ha

s t

he

sa

me

te

mp

era

ture

.

•C

on

clu

sio

n:

Tw

o s

yste

ms a

re in

th

erm

al

eq

uili

bri

um

if a

nd

on

ly if th

ey h

ave

th

e s

am

e

tem

pe

ratu

re.

K. H

eat

an

d T

em

pera

ture

2. T

he

rmo

me

ters

an

d T

em

pe

ratu

re S

ca

les

Ce

lsiu

s te

mp

era

ture

sca

le/L

iqu

id-i

n-t

ub

e

the

rmo

me

ter

•T

o m

ake

th

e liq

uid

-in

-tu

be

de

vic

e in

to a

use

ful

the

rmo

me

ter,

we

ne

ed

to

ma

rk a

sca

le o

n t

he

tu

be

wa

ll w

ith

nu

mb

ers

on

it.

•T

he

nu

mb

ers

are

arb

itra

ry a

nd

ma

ny n

um

be

r

�2

01

0 H

erb

ert

B. D

om

ing

o

•T

he

nu

mb

ers

are

arb

itra

ry a

nd

ma

ny n

um

be

r sch

em

es w

ere

use

d in

th

e p

ast.

•S

up

po

se

we

la

be

l th

e t

he

rmo

me

ter’

s liq

uid

le

ve

l a

t th

e f

ree

zin

g t

em

pe

ratu

re o

f p

ure

wa

ter

“ze

ro”

an

d th

e le

ve

l a

t b

oili

ng

te

mp

era

ture

“1

00

”, a

nd

d

ivid

e th

e d

ista

nce

be

twe

en

th

e t

wo

pts

in

to 1

00

e

qu

al in

terv

als

ca

lled

de

gre

es.

Page 5: material. • To use temperature as a measure of hotness and … · 2020-04-08 · K. Heat and Temperature 1. Temperature & Thermal Equilibrium Thermometer • First, select any measurable

K. H

eat

an

d T

em

pera

ture

2. T

he

rmo

me

ters

an

d T

em

pe

ratu

re S

ca

les

Ce

lsiu

s te

mp

era

ture

sca

le/L

iqu

id-i

n-t

ub

e

the

rmo

me

ter

•W

e g

et a

Ce

lsiu

s t

em

pe

ratu

re s

ca

le (

form

erl

y

ca

lled

th

e c

en

tig

rad

e s

ca

le in

En

glis

h-s

pe

akin

g

co

un

trie

s).

�2

01

0 H

erb

ert

B. D

om

ing

o

•C

els

ius te

mp

era

ture

fo

r a

sta

te c

old

er

tha

n

fre

ezin

g w

ate

r is

a n

eg

ative

nu

mb

er.

K. H

eat

an

d T

em

pera

ture

2. T

he

rmo

me

ters

an

d T

em

pe

ratu

re S

ca

les

Bim

eta

llic s

trip

th

erm

om

ete

r

•A

no

the

r co

mm

on

th

erm

om

ete

r

use

s a

bim

eta

llic s

trip

, m

ad

e b

y

bo

nd

ing

tw

o d

iffe

ren

t m

eta

ls

tog

eth

er.

�2

01

0 H

erb

ert

B. D

om

ing

o

•W

he

n te

mp

era

ture

of co

mp

osite

str

ip in

cre

ase

s, o

ne

me

tal e

xp

an

ds

mo

re t

ha

n t

he

oth

er

an

d t

he

str

ip

be

nd

s.

•A

s s

ho

wn

th

e p

oin

ter

rota

tes in

resp

on

se

to

te

mp

era

ture

ch

an

ge

s.

Page 6: material. • To use temperature as a measure of hotness and … · 2020-04-08 · K. Heat and Temperature 1. Temperature & Thermal Equilibrium Thermometer • First, select any measurable

K. H

eat

an

d T

em

pera

ture

2. T

he

rmo

me

ters

an

d T

em

pe

ratu

re S

ca

les

Re

sis

tan

ce

th

erm

om

ete

r

•T

he

ch

an

gin

g e

lectr

ica

l re

sis

tan

ce

of a

co

il o

f fin

e

wir

e, a

ca

rbo

n c

ylin

de

r, o

r a

ge

rma

niu

m c

rysta

l is

m

ea

su

red

.

•S

ince

re

sis

tan

ce

ca

n b

e m

ea

su

red

ve

ry p

recis

ely

, re

sis

tan

ce

th

erm

om

ete

rs a

re m

ore

pre

cis

e th

an

�2

01

0 H

erb

ert

B. D

om

ing

o

resis

tan

ce

th

erm

om

ete

rs a

re m

ore

pre

cis

e th

an

o

the

r ty

pe

s o

f th

erm

om

ete

rs.

K. H

eat

an

d T

em

pera

ture

2. T

he

rmo

me

ters

an

d T

em

pe

ratu

re S

ca

les

Th

erm

op

ile

•A

n e

ar

the

rmo

me

ter

is a

typ

e o

f d

evic

e c

alle

d a

the

rmo

pile

.

•It

me

asu

res t

he

am

ou

nt

of in

fra

red

ra

dia

tio

n

em

itte

d b

y t

he

ea

rdru

m,

wh

ich

in

dic

ate

s th

e

�2

01

0 H

erb

ert

B. D

om

ing

o

em

itte

d b

y t

he

ea

rdru

m,

wh

ich

in

dic

ate

s th

e

ea

rdru

m’s

te

mp

era

ture

.

•A

dva

nta

ge

of

this

te

ch

niq

ue

is it

do

es n

ot

req

uir

e

a p

hysic

al co

nta

ct o

f th

e t

he

rmo

me

ter

with

th

e

ea

rdru

m.

Page 7: material. • To use temperature as a measure of hotness and … · 2020-04-08 · K. Heat and Temperature 1. Temperature & Thermal Equilibrium Thermometer • First, select any measurable

K. H

eat

an

d T

em

pera

ture

2. T

he

rmo

me

ters

an

d T

em

pe

ratu

re S

ca

les

Fa

hre

nh

eit t

em

pe

ratu

re s

ca

le

•T

his

te

mp

era

ture

sca

le is u

se

d in

da

ily life

in

th

e

Un

ite

d S

tate

s.

•T

he

fre

ezin

g t

em

pe

ratu

re o

f w

ate

r is

32

°F.

•T

he

bo

ilin

g t

em

pe

ratu

re o

f w

ate

r is

21

2°F

.

�2

01

0 H

erb

ert

B. D

om

ing

o

•T

he

bo

ilin

g t

em

pe

ratu

re o

f w

ate

r is

21

2°F

.

•B

oth

are

me

asu

red

at

sta

nd

ard

atm

osp

he

ric

pre

ssu

re.

•T

he

re a

re 1

80

de

gre

es b

etw

ee

n f

ree

zin

g a

nd

bo

ilin

g, co

mp

are

d t

o C

els

ius s

ca

le (

10

0 d

eg

ree

s).

K. H

eat

an

d T

em

pera

ture

17

.2 T

he

rmo

me

ters

an

d T

em

pe

ratu

re S

ca

les

Co

nve

rsio

n b

etw

ee

n F

ah

ren

he

it/C

els

ius t

em

pe

ratu

re

sca

les

•T

o c

on

ve

rt f

rom

Ce

lsiu

s t

o F

ah

ren

he

it

)1(3

259

°+

=C

FT

T

�2

01

0 H

erb

ert

B. D

om

ing

o

•T

o c

on

ve

rt f

rom

Fa

hre

nh

eit t

o C

els

ius

5

)2(

)3

2(

95°

−=

FC

TT

Page 8: material. • To use temperature as a measure of hotness and … · 2020-04-08 · K. Heat and Temperature 1. Temperature & Thermal Equilibrium Thermometer • First, select any measurable

K. H

eat

an

d T

em

pera

ture

2. T

he

rmo

me

ters

an

d T

em

pe

ratu

re S

ca

les

Te

mp

era

ture

in

terv

al

•It

is im

po

rta

nt

to d

iffe

ren

tia

te b

etw

ee

n a

n a

ctu

al

tem

pe

ratu

re a

nd

a t

em

pe

ratu

re in

terv

al.

•A

ctu

al te

mp

era

ture

of

20

°C is s

tate

d a

s 2

0°C

(tw

en

ty d

eg

ree

s C

els

ius).

�2

01

0 H

erb

ert

B. D

om

ing

o

(tw

en

ty d

eg

ree

s C

els

ius).

•A

te

mp

era

ture

in

terv

al o

f 2

0°is

20

C°(t

we

nty

Ce

lsiu

s d

eg

ree

s).

K. H

eat

an

d T

em

pera

ture

2. T

he

rmo

me

ters

an

d T

em

pe

ratu

re S

ca

les

Ke

lvin

te

mp

era

ture

sca

le

•It

wa

s n

am

ed

aft

er

Bri

tish

ph

ysic

ist L

ord

Ke

lvin

.

•T

he

un

its (

K)

are

th

e s

am

e s

ize

as t

ho

se

on

th

e

Ce

lsiu

s s

ca

le, b

ut

ze

ro is s

hifte

d s

o t

ha

t

0 K

= −

27

3.1

5°C

an

d 2

73

.15

K =

0°C

�2

01

0 H

erb

ert

B. D

om

ing

o

0 K

= −

27

3.1

5°C

an

d 2

73

.15

K =

0°C

)3(

15

.2

73

+=

CK

TT

Page 9: material. • To use temperature as a measure of hotness and … · 2020-04-08 · K. Heat and Temperature 1. Temperature & Thermal Equilibrium Thermometer • First, select any measurable

K. H

eat

an

d T

em

pera

ture

2. T

he

rmo

me

ters

an

d T

em

pe

ratu

re S

ca

les

•In

SI

no

me

ncla

ture

, “d

eg

ree

” is

no

t u

se

d w

ith

Ke

lvin

sca

le.

•2

93

K is r

ea

d a

s “

29

3 k

elv

ins”,

no

t “d

eg

ree

s

Ke

lvin

.

•W

e c

ap

ita

lize

Ke

lvin

wh

en

it re

fers

to

th

e

�2

01

0 H

erb

ert

B. D

om

ing

o

•W

e c

ap

ita

lize

Ke

lvin

wh

en

it re

fers

to

th

e

tem

pe

ratu

re s

ca

le.

•H

ow

eve

r, t

he

un

it o

f

tem

pe

ratu

re is th

e

ke

lvin

, w

hic

h is n

ot

ca

pita

lize

d.

K. H

eat

an

d T

em

pera

ture

Ex

am

ple

1. T

em

pe

ratu

re C

on

ve

rsio

n

Wh

at a

re t

he

eq

uiv

ale

nt

Ce

lsiu

s a

nd

Ke

lvin

tem

pe

ratu

res o

f 5

0.0

°F?

�2

01

0 H

erb

ert

B. D

om

ing

o

Page 10: material. • To use temperature as a measure of hotness and … · 2020-04-08 · K. Heat and Temperature 1. Temperature & Thermal Equilibrium Thermometer • First, select any measurable

K. H

eat

an

d T

em

pera

ture

Ex

am

ple

1. (S

OL

N)

�2

01

0 H

erb

ert

B. D

om

ing

o

K. H

eat

an

d T

em

pera

ture

Te

mp

era

ture

Co

nv

ers

ion

�2

01

0 H

erb

ert

B. D

om

ing

o

Page 11: material. • To use temperature as a measure of hotness and … · 2020-04-08 · K. Heat and Temperature 1. Temperature & Thermal Equilibrium Thermometer • First, select any measurable

K. H

eat

an

d T

em

pera

ture

2. T

he

rmo

me

ters

an

d T

em

pe

ratu

re S

ca

les

Re

latio

nsh

ip b

etw

ee

n d

iffe

ren

t sca

les

�2

01

0 H

erb

ert

B. D

om

ing

o

Eqn 1

7.5

K. H

eat

an

d T

em

pera

ture

2. T

he

rmo

me

ters

an

d T

em

pe

ratu

re S

ca

les

Ab

so

lute

te

mp

era

ture

sca

le

•T

he

Ke

lvin

te

mp

era

ture

sca

le is c

alle

d a

n

ab

so

lute

te

mp

era

ture

sca

le.

•It

s z

ero

po

int

(T=

0 K

= 2

73

.15

°C)

is c

alle

d a

n

ab

so

lute

ze

ro.

�2

01

0 H

erb

ert

B. D

om

ing

o

ab

so

lute

ze

ro.

Page 12: material. • To use temperature as a measure of hotness and … · 2020-04-08 · K. Heat and Temperature 1. Temperature & Thermal Equilibrium Thermometer • First, select any measurable

K. H

eat

an

d T

em

pera

ture

3. T

he

rma

l E

xp

an

sio

n

•M

ost m

ate

ria

ls e

xp

an

d w

he

n t

he

ir te

mp

era

ture

incre

ase

s.

•E

xa

mp

les o

f th

erm

al e

xp

an

sio

n:

–e

xp

an

din

g liq

uid

in

a liq

uid

-in

-tu

be

the

rmo

me

ter,

�2

01

0 H

erb

ert

B. D

om

ing

o

the

rmo

me

ter,

–b

en

din

g b

ime

talli

c s

trip

s,

–lo

ose

nin

g a

me

tal ja

r lid

by r

un

nin

g h

ot

wa

ter

ove

r it.

K. H

eat

an

d T

em

pera

ture

3. T

he

rma

l E

xp

an

sio

n

Lin

ea

r E

xp

an

sio

n

•A

ro

d o

f m

ate

ria

l h

as a

le

ng

th L

0a

t so

me

in

itia

l

tem

pe

ratu

re T

0.

•W

he

n te

mp

era

ture

ch

an

ge

s b

y �

T,

len

gth

ch

an

ge

s b

y �

L

�2

01

0 H

erb

ert

B. D

om

ing

o

ch

an

ge

s b

y �

L

•E

xp

eri

me

nts

sh

ow

th

at if �

Tis

no

t to

o la

rge

(le

ss

tha

n 1

00

°C o

r so

), �

Lis

dir

ectly p

rop

ort

ion

al to

�T

.

•If

tw

o r

od

s m

ad

e o

f sa

me

ma

teri

al h

ave

sa

me

tem

pe

ratu

re c

ha

ng

e,

bu

t o

ne

is tw

ice

as lo

ng

,

the

n c

ha

ng

e in

its

le

ng

th is a

lso

twic

e a

s g

rea

t.

Page 13: material. • To use temperature as a measure of hotness and … · 2020-04-08 · K. Heat and Temperature 1. Temperature & Thermal Equilibrium Thermometer • First, select any measurable

K. H

eat

an

d T

em

pera

ture

3. T

he

rma

l E

xp

an

sio

n

Lin

ea

r E

xp

an

sio

n

•T

he

refo

re, �

Lm

ust a

lso

be

pro

po

rtio

na

l to

L0.

•In

tro

du

ce

a p

rop

ort

ion

alit

y c

on

sta

nt

α(v

ari

es

acco

rdin

g to

typ

e o

f m

ate

ria

ls),

we

ge

t )4(

TL

L∆

=∆

α

�2

01

0 H

erb

ert

B. D

om

ing

o

)4(

0T

LL

∆=

∆α

()

)5(

10

00

0T

LT

LL

LL

L∆

+=

∆+

=∆

+=

αα

•If

a b

od

y h

as le

ng

th L

0a

t te

mp

era

ture

T0, th

en

its le

ng

th L

at te

mp

era

ture

T=

T0

+ �

Tis

K. H

eat

an

d T

em

pera

ture

3. T

he

rma

l E

xp

an

sio

n

Lin

ea

r E

xp

an

sio

n

•T

he

co

nsta

nt

αw

hic

h d

escri

be

s th

e t

he

rma

l

exp

an

sio

n p

rop

ert

ies o

f a

pa

rtic

ula

r m

ate

ria

l is

ca

lled

th

e c

oe

ffic

ien

t o

f lin

ea

r e

xp

an

sio

n.

•It

s u

nits a

re K

-1o

r (°

C)-

1.

�2

01

0 H

erb

ert

B. D

om

ing

o

•It

s u

nits a

re K

or

(°C

).

•T

hu

s L

co

uld

be

th

e t

hic

kn

ess o

f a

ro

d,

sid

e le

ng

th

of a

sq

ua

re s

he

et,

or

the

dia

me

ter

of a

ho

le.

Page 14: material. • To use temperature as a measure of hotness and … · 2020-04-08 · K. Heat and Temperature 1. Temperature & Thermal Equilibrium Thermometer • First, select any measurable

K. H

eat

an

d T

em

pera

ture

3. T

he

rma

l E

xp

an

sio

n

•If

a s

olid

ob

ject

ha

s a

ho

le in

it,

wh

at

ha

pp

en

s

to th

e s

ize

of

it w

he

n t

he

te

mp

era

ture

of

the

ob

ject in

cre

ase

s?

•C

om

mo

n m

isco

nce

ptio

n is th

at th

e m

ate

ria

l

will

exp

an

d in

to t

he

ho

le.

�2

01

0 H

erb

ert

B. D

om

ing

o

•T

he

fa

ct is

th

e h

ole

exp

an

ds a

lon

g w

ith

th

e

ob

ject.

•E

ve

ry lin

ea

r d

ime

nsio

n

of a

n o

bje

ct

ch

an

ge

s in

the

sa

me

wa

y w

he

n

tem

pe

ratu

re c

ha

ng

es.

K. H

eat

an

d T

em

pera

ture

Su

rfa

ce

Ex

pa

ns

ion

Do H

ole

s E

xpand o

r C

ontr

act

When t

he T

em

pera

ture

Incre

ases?

�2

01

0 H

erb

ert

B. D

om

ing

o

Page 15: material. • To use temperature as a measure of hotness and … · 2020-04-08 · K. Heat and Temperature 1. Temperature & Thermal Equilibrium Thermometer • First, select any measurable

K. H

eat

an

d T

em

pera

ture

3. T

he

rma

l E

xp

an

sio

n

Lin

ea

r E

xp

an

sio

n

•N

ote

th

e d

ire

ct p

rop

ort

ion

alit

y e

xp

resse

d in

Eq

n4

.

•It

is a

pp

roxim

ate

ly c

orr

ect o

nly

fo

r su

ffic

ien

tly s

ma

ll

tem

pe

ratu

re c

ha

ng

es.

�2

01

0 H

erb

ert

B. D

om

ing

o

K. H

eat

an

d T

em

pera

ture

3. T

he

rma

l E

xp

an

sio

n

Vo

lum

e E

xp

an

sio

n

•T

he

co

nsta

nt

βch

ara

cte

rize

s t

he

vo

lum

e

exp

an

sio

n p

rop

ert

ies o

f a

pa

rtic

ula

r m

ate

ria

l.

•It

is c

alle

d t

he

co

eff

icie

nt o

f vo

lum

e e

xp

an

sio

n

•It

s u

nits a

re K

-1o

r (°

C)-

1.

�2

01

0 H

erb

ert

B. D

om

ing

o

•It

s u

nits a

re K

-1o

r (°

C)-

1.

Page 16: material. • To use temperature as a measure of hotness and … · 2020-04-08 · K. Heat and Temperature 1. Temperature & Thermal Equilibrium Thermometer • First, select any measurable

K. H

eat

an

d T

em

pera

ture

3. T

he

rma

l E

xp

an

sio

n

Vo

lum

e E

xp

an

sio

n

•In

cre

asin

g te

mp

era

ture

usu

ally

ca

use

s a

n in

cre

ase

in v

olu

me

fo

r b

oth

so

lid a

nd

liq

uid

ma

teri

als

.

•E

xp

eri

me

nts

sh

ow

th

at if te

mp

era

ture

ch

an

ge

�T

is

no

t to

o g

rea

t (l

ess th

an

10

0°C

), t

he

in

cre

ase

in

�2

01

0 H

erb

ert

B. D

om

ing

o

no

t to

o g

rea

t (l

ess th

an

10

0°C

), t

he

in

cre

ase

in

vo

lum

e �

Vis

ap

pro

xim

ate

ly p

rop

ort

ion

al to

bo

th

tem

pe

ratu

re c

ha

ng

e �

Ta

nd

in

itia

l vo

lum

e V

0;

)6(

0T

VV

∆=

∆β

K. H

eat

an

d T

em

pera

ture

�2

01

0 H

erb

ert

B. D

om

ing

o

This

gap in t

he r

oadw

ay o

f a b

ridge is

calle

d a

n e

xpansio

n join

t; it

allo

ws t

he

bridge t

o e

xpand a

nd c

ontr

act.

Page 17: material. • To use temperature as a measure of hotness and … · 2020-04-08 · K. Heat and Temperature 1. Temperature & Thermal Equilibrium Thermometer • First, select any measurable

K. H

eat

an

d T

em

pera

ture

Ex

am

ple

2.

Le

ng

th c

ha

ng

e d

ue

to

te

mp

era

ture

ch

an

ge

I

A s

urv

eyo

r u

se

s a

ste

el m

ea

su

rin

g t

ap

e t

ha

t is

exa

ctly 5

0.0

00

m lo

ng

at a

te

mp

era

ture

of 2

0°C

.

Wh

at is

its

le

ng

th o

n a

ho

t su

mm

er

da

y w

he

n t

he

tem

pe

ratu

re is 3

5 °

C.

�2

01

0 H

erb

ert

B. D

om

ing

o

15

K1

02.

1−

−×

=st

eel

α

K. H

eat

an

d T

em

pera

ture

Ex

am

ple

2.

(SO

LN

)

Te

mp

era

ture

ch

an

ge

is �

T=

T−

T0

= 1

5C

°, s

o th

e

ch

an

ge

in

le

ng

th �

La

nd

th

e f

ina

l le

ng

th L

= L

0+

�L

are

()(

)()

mm

0.9

m1

00.

9

K1

5m

50

K1

02.

13

15

0

=

×=

∆=

∆−

−−

TL

�2

01

0 H

erb

ert

B. D

om

ing

o

Th

us th

e le

ng

th a

t 3

5°C

is 5

0.0

09

m.

m0

09

.5

0m

00

9.

0m

00

0.

50

mm

0.9

m1

00.

9

0=

+=

+=

=

LL

L

Page 18: material. • To use temperature as a measure of hotness and … · 2020-04-08 · K. Heat and Temperature 1. Temperature & Thermal Equilibrium Thermometer • First, select any measurable

K. H

eat

an

d T

em

pera

ture

Ex

am

ple

3.

Le

ng

th C

ha

ng

e D

ue

to

Te

mp

era

ture

Ch

an

ge

II

In e

xa

mp

le 2

, th

e s

urv

eyo

r u

se

s th

e m

ea

su

rin

g t

ap

e

to m

ea

su

re a

dis

tan

ce

wh

en

th

e te

mp

era

ture

is 3

5°C

;

the

va

lue

th

at sh

e r

ea

ds o

ff th

e t

ap

e is 3

5.7

94

m.

Wh

at is

th

e a

ctu

al d

ista

nce

? A

ssu

me

th

at th

e t

ap

e is

ca

libra

ted

fo

r u

se

at

20

°C.

�2

01

0 H

erb

ert

B. D

om

ing

o

K. H

eat

an

d T

em

pera

ture

Ex

am

ple

3. L

en

gth

Ch

an

ge

Du

e t

o T

em

pe

ratu

re C

ha

ng

e II

Th

e r

atio

L/L

0is

(5

0.0

09

m)/

(50

.00

0 m

), s

o t

he

tru

e

dis

tan

ce

is

()

mm

mm800

.35

794

.35

000

.50

009

.50

=

�2

01

0 H

erb

ert

B. D

om

ing

o

Page 19: material. • To use temperature as a measure of hotness and … · 2020-04-08 · K. Heat and Temperature 1. Temperature & Thermal Equilibrium Thermometer • First, select any measurable

K. H

eat

an

d T

em

pera

ture

Exam

ple

4. V

olu

me c

han

ge d

ue t

o t

em

pera

ture

ch

an

ge

A g

lass fla

sk w

ith

vo

lum

e 2

00

cm

3is

fill

ed

to

th

e b

rim

with

me

rcu

ry a

t 2

0°C

. H

ow

mu

ch

me

rcu

ry o

ve

rflo

ws

wh

en

th

e t

em

pe

ratu

re o

f th

e s

yste

m is r

ais

ed

to

10

0°C

? T

he

co

eff

icie

nt o

f lin

ea

r e

xp

an

sio

n o

f th

e

gla

ss is 0

.40

×1

0-5

K-1

.

�2

01

0 H

erb

ert

B. D

om

ing

o

βm

ercu

ry=

18

×1

0-5

K-1

K. H

eat

an

d T

em

pera

ture

Ex

am

ple

4.

(SO

LN

)

Incre

ase

in

vo

lum

e o

f g

lass f

lask

()(

) ()

3

31

5

0

20

10

02

00

10

2.1

CC

cm

K

=

°−

°×

=

∆=

−−

TV

Vg

lass

gla

ssβ

()

15

11

10

2.1

10

40

.0

33

−−

−−

×=

×=

=K

Kg

lass

gla

ssα

β

�2

01

0 H

erb

ert

B. D

om

ing

o

Incre

ase

in

vo

lum

e o

f m

erc

ury

is

31

9.

0cm

=

()(

) ()

3

31

5

0

9.2

20

10

02

00

10

18

cm

CC

cm

K

=

°−

°×

=

∆=

−−

TV

Vm

ercu

rym

ercu

ryβ

Page 20: material. • To use temperature as a measure of hotness and … · 2020-04-08 · K. Heat and Temperature 1. Temperature & Thermal Equilibrium Thermometer • First, select any measurable

K. H

eat

an

d T

em

pera

ture

Ex

am

ple

4.

(SO

LN

)

Vo

lum

e o

f m

erc

ury

th

at o

ve

rflo

ws

33

37.

21

9.

09.

2cm

cm

cm

=−

=∆

−∆

gla

ssm

ercu

ryV

V

�2

01

0 H

erb

ert

B. D

om

ing

o

K. H

eat

an

d T

em

pera

ture

3. T

he

rma

l E

xp

an

sio

n

Th

erm

al e

xp

an

sio

n o

f w

ate

r

•W

ate

r in

th

e t

em

pe

ratu

re r

an

ge

of

0°C

to

4°C

,

de

cre

ase

s in

vo

lum

e w

ith

in

cre

asin

g t

em

pe

ratu

re.

•In

th

e a

bo

ve

ra

ng

e,

its c

oe

ffic

ien

t o

f vo

lum

e

exp

an

sio

n is n

eg

ative

.

�2

01

0 H

erb

ert

B. D

om

ing

o

exp

an

sio

n is n

eg

ative

.

•A

bo

ve

4°C

, w

ate

r e

xp

an

ds w

he

n h

ea

ted

, h

en

ce

wa

ter

ha

s its

gre

ate

st

de

nsity a

t 4°C

.

•W

ate

r a

lso

exp

an

ds w

he

n it fr

ee

ze

s.

•T

his

an

om

alo

us b

eh

avio

r o

f w

ate

r h

as a

n

imp

ort

an

t e

ffe

ct o

n p

lan

t a

nd

wa

ter

life

in

la

ke

s,

pa

rtic

ula

rly d

uri

ng

win

ter.

Page 21: material. • To use temperature as a measure of hotness and … · 2020-04-08 · K. Heat and Temperature 1. Temperature & Thermal Equilibrium Thermometer • First, select any measurable

K. H

eat

an

d T

em

pera

ture

4. Q

ua

nti

ty o

f H

ea

t

Qu

an

tity

of

he

at

•E

ne

rgy tra

nsfe

r ta

ke

s p

lace

so

lely

be

ca

use

of a

tem

pe

ratu

re d

iffe

ren

ce

ca

lled

he

at

flo

w o

r h

ea

t

tra

nsfe

r.

•E

ne

rgy tra

nsfe

rre

d in

th

is w

ay is c

alle

d h

ea

t.

�2

01

0 H

erb

ert

B. D

om

ing

o

•E

ne

rgy tra

nsfe

rre

d in

th

is w

ay is c

alle

d h

ea

t.

•S

ir J

am

es J

ou

le

dis

co

ve

red

th

at

tem

pe

ratu

re r

ise

is

dir

ectly p

rop

ort

ion

al

to th

e a

mo

un

t o

f

wo

rk d

on

e.

K. H

eat

an

d T

em

pera

ture

Cats

, such a

s t

his

Bengal

tiger,

oft

en p

ant

to g

et

rid o

f

excess h

eat.

(P

hoto

Dis

c

�2

01

0 H

erb

ert

B. D

om

ing

o

Blu

e/P

hoto

Dis

c,

Inc./

Gett

y

Images)

Page 22: material. • To use temperature as a measure of hotness and … · 2020-04-08 · K. Heat and Temperature 1. Temperature & Thermal Equilibrium Thermometer • First, select any measurable

K. H

eat

an

d T

em

pera

ture

4. Q

ua

nti

ty o

f H

ea

t

•K

ee

p c

lea

rly in

min

d t

he

dis

tin

ctio

n b

etw

ee

n

tem

pe

ratu

re a

nd

he

at.

•T

em

pe

ratu

re d

ep

en

ds o

f th

e p

hysic

al sta

te o

f a

ma

teri

al a

nd

is a

qu

an

tita

tive

de

scri

ptio

n o

f its h

otn

ess o

r co

ldn

ess.

•H

ea

t a

lwa

ys r

efe

r to

en

erg

y in

tra

nsit fro

m o

ne

b

od

y o

r syste

m to

an

oth

er

be

ca

use

of a

�2

01

0 H

erb

ert

B. D

om

ing

obo

dy o

r syste

m to

an

oth

er

be

ca

use

of a

te

mp

era

ture

diffe

ren

ce

, n

eve

r to

th

e a

mo

un

t o

f e

ne

rgy c

on

tain

ed

with

in a

pa

rtic

ula

r syste

m.

•W

e c

ha

ng

e t

he

te

mp

era

ture

of a

bo

dy b

y

ad

din

g h

ea

t to

it o

r re

mo

vin

g h

ea

t a

wa

y f

rom

it.

K. H

eat

an

d T

em

pera

ture

4. Q

ua

nti

ty o

f H

ea

t

Qu

an

tity

of

he

at

•W

e d

efin

e a

un

it o

f q

ua

ntity

of h

ea

t b

ase

d o

n

tem

pe

ratu

re c

ha

ng

es o

f so

me

sp

ecific

ma

teri

al.

•T

he

ca

lori

e is d

efin

ed

as th

e a

mo

un

t o

f h

ea

t

req

uir

ed

to

ra

ise

th

e t

em

pe

ratu

re o

f o

ne

gra

m o

f

�2

01

0 H

erb

ert

B. D

om

ing

o

req

uir

ed

to

ra

ise

th

e t

em

pe

ratu

re o

f o

ne

gra

m o

f

wa

ter

by o

ne

C°.

•C

orr

esp

on

din

g u

nit o

f h

ea

t u

sin

g F

ah

ren

he

it

de

gre

es a

nd

Im

pe

ria

l u

nits is th

e B

ritish

th

erm

al

un

it (

Btu

).

•O

ne

Btu

is th

e q

ua

ntity

of h

ea

t re

qu

ire

d t

o r

ais

e th

e

tem

pe

ratu

re o

f o

ne

po

un

d o

f w

ate

r b

y o

ne

F°.

Page 23: material. • To use temperature as a measure of hotness and … · 2020-04-08 · K. Heat and Temperature 1. Temperature & Thermal Equilibrium Thermometer • First, select any measurable

K. H

eat

an

d T

em

pera

ture

4. Q

ua

nti

ty o

f H

ea

t

Qu

an

tity

of

he

at

•T

hu

s,

1 c

al =

4.1

86

J

1 k

ca

l =

41

86

J

1 B

tu =

25

2 c

al =

10

55

J

•T

he

ca

lori

e is n

ot

a f

un

da

me

nta

l S

I u

nit, in

ste

ad

�2

01

0 H

erb

ert

B. D

om

ing

o

•T

he

ca

lori

e is n

ot

a f

un

da

me

nta

l S

I u

nit, in

ste

ad

jou

le is u

se

d a

s th

e b

asic

un

it o

f e

ne

rgy in

all

form

s, in

clu

din

g h

ea

t.

K. H

eat

an

d T

em

pera

ture

4. Q

ua

nti

ty o

f H

ea

t

Sp

ecific

he

at

•Q

is u

se

d t

o r

ep

rese

nt

qu

an

tity

of

he

at.

•Q

ua

ntity

of

he

at

req

uir

ed

to

in

cre

ase

te

mp

era

ture

of a

ma

ss m

of

ce

rta

in m

ate

ria

l fr

om

T1

to T

2is

fou

nd

to

be

ap

pro

xim

ate

ly p

rop

ort

ion

al to

�2

01

0 H

erb

ert

B. D

om

ing

o

fou

nd

to

be

ap

pro

xim

ate

ly p

rop

ort

ion

al to

tem

pe

ratu

re c

ha

ng

e �

T=

T2

−T

1. It

is a

lso

pro

po

rtio

na

l to

ma

ss m

of th

e m

ate

ria

l. T

hu

s,

we

ha

ve

!

"#$

%&

"#c

as t

he

sp

ecific

he

at

of th

e m

ate

ria

l.

)7(

Tm

cQ

∆=

Page 24: material. • To use temperature as a measure of hotness and … · 2020-04-08 · K. Heat and Temperature 1. Temperature & Thermal Equilibrium Thermometer • First, select any measurable

K. H

eat

an

d T

em

pera

ture

4. Q

ua

nti

ty o

f H

ea

t

•H

ea

t is

alw

ays e

ne

rgy in

tra

nsit a

s a

re

su

lt o

f

tem

pe

ratu

re d

iffe

ren

ce

.

•T

he

re is n

o s

uch

th

ing

as “

the

am

ou

nt

of h

ea

t

in a

bo

dy”.

�2

01

0 H

erb

ert

B. D

om

ing

o

K. H

eat

an

d T

em

pera

ture

4. Q

ua

nti

ty o

f H

ea

t

Sp

ecific

he

at

•T

he

sp

ecific

he

at

of

a m

ate

ria

l a

lwa

ys d

ep

en

ds o

n

the

in

itia

l te

mp

era

ture

an

d t

he

te

mp

era

ture

in

terv

al.

•S

pe

cific

he

at

of w

ate

r is

ap

pro

xim

ate

ly

41

90

J/k

g·K

�2

01

0 H

erb

ert

B. D

om

ing

o

41

90

J/k

g·K

1 c

al/g

·C°

1 B

tu/lb

·F°

Page 25: material. • To use temperature as a measure of hotness and … · 2020-04-08 · K. Heat and Temperature 1. Temperature & Thermal Equilibrium Thermometer • First, select any measurable

K. H

eat

an

d T

em

pera

ture

Ex

am

ple

5.

Fe

ed

a c

old

, s

tarv

e a

fe

ve

r

Du

rin

g a

bo

ut

with

flu

, a

n 8

0-k

g m

an

ra

n a

fe

ve

r o

f

39

.0°C

(1

02

.2°F

) in

ste

ad

of th

e n

orm

al b

od

y

tem

pe

ratu

re o

f 3

7.0

°C (

98

.6°F

). A

ssu

min

g t

ha

t th

e

hu

ma

n b

od

y is m

ostly w

ate

r, h

ow

mu

ch

he

at

is

req

uir

ed

to

ra

ise

his

te

mp

era

ture

by th

at a

mo

un

t?

�2

01

0 H

erb

ert

B. D

om

ing

o

K. H

eat

an

d T

em

pera

ture

Ex

am

ple

5.

(SO

LN

) ()(

)()

JK

KJ/k

gkg

51

07.

60.

24

19

08

=⋅

=∆

=T

mc

Q

�2

01

0 H

erb

ert

B. D

om

ing

o

Page 26: material. • To use temperature as a measure of hotness and … · 2020-04-08 · K. Heat and Temperature 1. Temperature & Thermal Equilibrium Thermometer • First, select any measurable

K. H

eat

an

d T

em

pera

ture

Ex

am

ple

6.

Ov

erh

ea

tin

g e

lec

tro

nic

s

Yo

u a

re d

esig

nin

g a

n e

lectr

on

ic c

ircu

it e

lem

en

t m

ad

e

of 2

3 m

g o

f sili

co

n.

Th

e e

lectr

ic c

urr

en

t th

rou

gh

it

ad

ds e

ne

rgy a

t th

e r

ate

of 7

.4 ×

10

-3J/s

. If

yo

ur

de

sig

n d

oe

sn

’t a

llow

an

y h

ea

t tr

an

sfe

r o

ut o

f th

e

ele

me

nt,

at

wh

at

rate

do

es its

te

mp

era

ture

in

cre

ase

?

Sp

ecific

he

at

of sili

co

n is 7

05

J/k

g⋅K

.

�2

01

0 H

erb

ert

B. D

om

ing

o

Sp

ecific

he

at

of sili

co

n is 7

05

J/k

g⋅K

.

K. H

eat

an

d T

em

pera

ture

Ex

am

ple

6.

(SO

LN

)

In o

ne

se

co

nd

, Q

= (

7.4

×1

0-3

J/s

)(1

s)

= 7

.4 ×

10

-3J.

Fro

m Q

= m

c�T

,'"

&(")%

'*)"

#+,%$-"#.$#/

$"#0

"+/$1#.0

() (

)K

KJ/k

gkg

J4

6.

07

05

10

23

10

4.7 6

3

=⋅

×

×=

=∆

mc

QT

�2

01

0 H

erb

ert

B. D

om

ing

o

() (

)K

J/k

gkg

70

51

02

3⋅

×m

c

Page 27: material. • To use temperature as a measure of hotness and … · 2020-04-08 · K. Heat and Temperature 1. Temperature & Thermal Equilibrium Thermometer • First, select any measurable

K. H

eat

an

d T

em

pera

ture

4. Q

ua

nti

ty o

f H

ea

t

•T

he

te

rm “

he

at

ca

pa

city”

is u

nfo

rtu

na

te

be

ca

use

it g

ive

s t

he

err

on

eo

us im

pre

ssio

n

tha

t a

bo

dy c

on

tain

s a

ce

rta

in a

mo

un

t o

f h

ea

t.

•R

em

em

be

r th

e h

ea

t is

en

erg

y in

tra

nsit to

or

fro

m a

bo

dy,

no

t th

e e

ne

rgy r

esid

ing

in

th

e

�2

01

0 H

erb

ert

B. D

om

ing

obo

dy.

K. H

eat

an

d T

em

pera

ture

5. C

alo

rim

etr

ya

nd

Ph

as

e C

ha

ng

es

•C

alo

rim

etr

ym

ea

ns “

me

asu

rin

g h

ea

t”.

Ph

ase

ch

an

ge

s

•T

he

te

rm p

ha

se

is u

se

d t

o d

escri

be

a s

pe

cific

sta

te

of m

att

er,

su

ch

as s

olid

, liq

uid

or

ga

s.

•T

he

co

mp

ou

nd

H2O

exis

ts in

th

e s

olid

ph

ase

as

ice

, liq

uid

ph

ase

as w

ate

r, a

nd

ga

se

ou

s p

ha

se

as

�2

01

0 H

erb

ert

B. D

om

ing

o

ice

, liq

uid

ph

ase

as w

ate

r, a

nd

ga

se

ou

s p

ha

se

as

ste

am

(a

lso

kn

ow

n a

s s

tate

s o

f m

att

er)

.

•A

tra

nsitio

n fro

m o

ne

ph

ase

to

an

oth

er

is c

alle

d

ph

ase

ch

an

ge

or

ph

ase

tra

nsitio

n.

•A

ph

ase

ch

an

ge

ta

ke

s p

lace

at a

de

fin

ite

te

mp

era

ture

, a

cco

mp

an

ied

by a

bso

rptio

n/e

mis

sio

n

of h

ea

t a

nd

a c

ha

ng

e in

vo

lum

e a

nd

de

nsity.

Page 28: material. • To use temperature as a measure of hotness and … · 2020-04-08 · K. Heat and Temperature 1. Temperature & Thermal Equilibrium Thermometer • First, select any measurable

K. H

eat

an

d T

em

pera

ture

5. C

alo

rim

etr

ya

nd

Ph

as

e C

ha

ng

es

Ph

ase

ch

an

ge

s

•T

o c

ha

ng

e 1

kg

of ic

e a

t 0°C

to

1 k

g o

f liq

uid

wa

ter

at

0°C

at

no

rma

l a

tmo

sp

he

ric p

ressu

re r

eq

uir

es

3.3

4 ×

10

5J o

f h

ea

t.

•H

ea

t re

qu

ire

d p

er

un

it m

ass is c

alle

d t

he

he

at

of

�2

01

0 H

erb

ert

B. D

om

ing

o

•H

ea

t re

qu

ire

d p

er

un

it m

ass is c

alle

d t

he

he

at

of

fusio

n (

or

late

nt h

ea

t o

f fu

sio

n),

de

no

ted

by L

f.

•F

or

wa

ter

at n

orm

al a

tmo

sp

he

ric p

ressu

re,

the

he

at o

f fu

sio

n is L

f=

3.3

4 ×

10

5J =

79

.6 c

al/g

=

14

3 B

tu/lb

•G

en

era

lly,

Q =

mL

f

•N

ote

th

at th

e a

bo

ve

pro

ce

ss is r

eve

rsib

le.

K. H

eat

an

d T

em

pera

ture

5. C

alo

rim

etr

ya

nd

Ph

as

e C

ha

ng

es

Ph

ase

ch

an

ge

s

•W

e n

ee

d t

o r

em

ove

he

at

to fre

eze

liq

uid

wa

ter

to

ice

at

0°C

, th

e m

ag

nitu

de

is th

e s

am

e e

xce

pt

tha

t Q

is n

eg

ative

be

ca

use

he

at

is r

em

ove

d.

•T

o c

ove

r b

oth

po

ssib

ilitie

s a

nd

oth

er

kin

ds o

f p

ha

se

�2

01

0 H

erb

ert

B. D

om

ing

o

•T

o c

ove

r b

oth

po

ssib

ilitie

s a

nd

oth

er

kin

ds o

f p

ha

se

ch

an

ge

s, w

e w

rite

•H

ea

t o

f fu

sio

n is d

iffe

ren

t fo

r d

iffe

ren

t m

ate

ria

ls a

nd

als

o v

ari

es s

om

ew

ha

t w

ith

pre

ssu

re.

)8(

mL

=

Page 29: material. • To use temperature as a measure of hotness and … · 2020-04-08 · K. Heat and Temperature 1. Temperature & Thermal Equilibrium Thermometer • First, select any measurable

K. H

eat

an

d T

em

pera

ture

5. C

alo

rim

etr

ya

nd

Ph

as

e C

ha

ng

es

Ph

ase

eq

uili

bri

um

•F

or

a g

ive

n m

ate

ria

l a

t a

ny g

ive

n p

ressu

re,

the

fr

ee

zin

g te

mp

era

ture

is th

e s

am

e a

s t

he

me

ltin

g

tem

pe

ratu

re.

•T

he

co

nd

itio

n w

he

re liq

uid

an

d s

olid

ph

ase

s c

an

co

exis

t is

ca

lled

ph

ase

eq

uili

bri

um

.

�2

01

0 H

erb

ert

B. D

om

ing

o

co

exis

t is

ca

lled

ph

ase

eq

uili

bri

um

.

He

at o

f va

po

riza

tio

n

•T

he

pre

vio

us p

ha

se

ch

an

ge

ca

n a

lso

be

ap

plie

d t

o

bo

ilin

g o

r e

va

po

ratio

n,

a tra

nsitio

n b

etw

ee

n t

he

liq

uid

an

d g

ase

ou

s p

ha

se

s.

•T

he

he

at n

ee

de

d is c

alle

d t

he

he

at

of va

po

riza

tio

n,

Lv

= 2

.25

6 ×

10

6J/k

g =

53

9 c

al/g

= 9

70

Btu

/lb

K. H

eat

an

d T

em

pera

ture

5. C

alo

rim

etr

ya

nd

Ph

as

e C

ha

ng

es

He

at o

f va

po

riza

tio

n

•L

ike

me

ltin

g,

bo

ilin

g is a

re

ve

rsib

le t

ran

sitio

n.

•W

he

n h

ea

t is

re

mo

ve

d f

rom

a g

as a

t b

oili

ng

tem

pe

ratu

re,

the

ga

s r

etu

rns t

o th

e liq

uid

ph

ase

,

tha

t is

, it c

on

de

nse

s.

�2

01

0 H

erb

ert

B. D

om

ing

o

tha

t is

, it c

on

de

nse

s.

•L

va

nd

bo

ilin

g t

em

pe

ratu

re o

f a

ma

teri

al d

ep

en

d o

n

pre

ssu

re.

•T

he

gra

ph

sh

ow

s h

ow

te

mp

era

ture

va

rie

s w

he

n w

e

ad

d h

ea

t co

ntin

uo

usly

to

a s

pe

cim

en

of

ice

with

initia

l te

mp

era

ture

be

low

0°C

, w

he

n it

rea

ch

es

me

ltin

g b

oili

ng

po

ints

.

Page 30: material. • To use temperature as a measure of hotness and … · 2020-04-08 · K. Heat and Temperature 1. Temperature & Thermal Equilibrium Thermometer • First, select any measurable

K. H

eat

an

d T

em

pera

ture

5. C

alo

rim

etr

ya

nd

Ph

as

e C

ha

ng

es

Heat of vaporization

�2

01

0 H

erb

ert

B. D

om

ing

o

Fig

17.1

8

K. H

eat

an

d T

em

pera

ture

5. C

alo

rim

etr

ya

nd

Ph

as

e C

ha

ng

es

Heat of vaporization

�2

01

0 H

erb

ert

B. D

om

ing

o

Page 31: material. • To use temperature as a measure of hotness and … · 2020-04-08 · K. Heat and Temperature 1. Temperature & Thermal Equilibrium Thermometer • First, select any measurable

K. H

eat

an

d T

em

pera

ture

5. C

alo

rim

etr

ya

nd

Ph

as

e C

ha

ng

es

Su

blim

atio

n

•S

om

e s

ub

sta

nce

s c

an

so

me

tim

es c

ha

ng

e d

ire

ctly

fro

m s

olid

to

th

e g

ase

ou

s p

ha

se

, a

pro

ce

ss w

e

ca

lled

su

blim

atio

n.

•T

he

co

rre

sp

on

din

g h

ea

t n

ee

de

d is t

he

he

at

of

�2

01

0 H

erb

ert

B. D

om

ing

o

•T

he

co

rre

sp

on

din

g h

ea

t n

ee

de

d is t

he

he

at

of

su

blim

atio

n,

Ls.

Su

pe

rco

ole

d

•V

ery

pu

re w

ate

r ca

n b

e c

oo

led

to

se

ve

ral d

eg

ree

s

be

low

th

e f

ree

zin

g t

em

pe

ratu

re w

ith

ou

t fr

ee

zin

g,

this

sta

te is d

escri

be

d a

s s

up

erc

oo

led

.

K. H

eat

an

d T

em

pera

ture

5. C

alo

rim

etr

ya

nd

Ph

as

e C

ha

ng

es

Su

pe

rco

ole

d

•V

ery

pu

re w

ate

r ca

n b

e c

oo

led

to

se

ve

ral d

eg

ree

s

be

low

th

e f

ree

zin

g t

em

pe

ratu

re w

ith

ou

t fr

ee

zin

g.

•T

his

sta

te is d

escri

be

d a

s s

up

erc

oo

led

an

d t

he

pri

ncip

le is a

pp

lied

in

“se

ed

ing

” clo

ud

s.

�2

01

0 H

erb

ert

B. D

om

ing

o

pri

ncip

le is a

pp

lied

in

“se

ed

ing

” clo

ud

s.

Su

pe

rhe

ate

d

•S

imila

rly, a

liq

uid

ca

n a

lso

be

su

pe

rhe

ate

d a

bo

ve

its n

orm

al b

oili

ng

te

mp

era

ture

.

Page 32: material. • To use temperature as a measure of hotness and … · 2020-04-08 · K. Heat and Temperature 1. Temperature & Thermal Equilibrium Thermometer • First, select any measurable

K. H

eat

an

d T

em

pera

ture

5. C

alo

rim

etr

ya

nd

Ph

as

e C

ha

ng

es

Eva

po

rative

co

olin

g

•T

em

pe

ratu

re c

on

tro

l m

ech

an

ism

of

ma

ny a

nim

als

ma

ke

s u

se

of h

ea

t o

f va

po

riza

tio

n t

o r

em

ove

he

at

fro

m th

e b

od

y.

•B

y r

em

ovin

g w

ate

r fr

om

th

e t

on

gu

e (

pa

ntin

g)

or

�2

01

0 H

erb

ert

B. D

om

ing

o

•B

y r

em

ovin

g w

ate

r fr

om

th

e t

on

gu

e (

pa

ntin

g)

or

fro

m th

e s

kin

(sw

ea

tin

g)

by v

ap

ori

zin

g w

ate

r, a

n

op

tim

um

bo

dy t

em

pe

ratu

re c

an

be

ma

inta

ine

d.

•It

is a

lso

use

d t

o c

oo

l b

uild

ing

s in

ho

t, d

ry c

lima

tes

an

d to

re

cir

cu

late

“u

se

d”

ste

am

in

co

al-

fire

d o

r

nu

cle

ar-

po

we

red

ele

ctr

ic-g

en

era

tin

g p

lan

ts.

K. H

eat

an

d T

em

pera

ture

5. C

alo

rim

etr

ya

nd

Ph

as

e C

ha

ng

es

He

at o

f co

mb

ustio

n

•C

he

mic

al re

actio

ns (

e.g

., c

om

bu

stio

n)

tha

t a

re

sim

ilar

to p

ha

se

ch

an

ge

as t

he

y in

vo

lve

de

fin

ite

qu

an

titie

s o

f h

ea

t.

He

at ca

lcu

latio

ns

�2

01

0 H

erb

ert

B. D

om

ing

o

He

at ca

lcu

latio

ns

•L

aw

of

ca

lori

me

try:

Wh

en

he

at

flo

w o

ccu

rs

be

twe

en

tw

o b

od

ies t

ha

t a

re iso

late

d fro

m t

he

ir

su

rro

un

din

gs, a

mo

un

t o

f h

ea

t lo

st b

y o

ne

bo

dy

mu

st e

qu

al th

e a

mo

un

t g

ain

ed

by t

he

oth

er.

•In

oth

er

wo

rds,

the

co

nse

rva

tio

n o

f e

ne

rgy.

Page 33: material. • To use temperature as a measure of hotness and … · 2020-04-08 · K. Heat and Temperature 1. Temperature & Thermal Equilibrium Thermometer • First, select any measurable

K. H

eat

an

d T

em

pera

ture

�2

01

0 H

erb

ert

B. D

om

ing

o

This

hig

hly

magnifie

d im

age s

how

s a

fabric t

hat

has b

een c

oate

d

with m

icro

scopic

balls

of heat-

resis

tant

pla

stic. T

he b

alls

conta

in a

substa

nce k

now

n a

s a

“phase-c

hange m

ate

rial,”

the m

eltin

g a

nd

freezin

g o

f w

hic

h a

bsorb

s a

nd r

ele

ases h

eat.

Such f

abrics

auto

matically

adju

st

in r

eaction t

o y

our

body h

eat

to h

elp

main

tain

a

consta

nt te

mpera

ture

next

to y

our

skin

. (C

ourt

esy O

utlast

Technolo

gie

s,

Bould

er,

CO

)

K. H

eat

an

d T

em

pera

ture

Exam

ple

7. T

em

pera

ture

ch

an

ge w

ith

no

ph

ase c

han

ge

A 0

.05

0 k

g m

eta

l b

olt is h

ea

ted

to

an

un

kn

ow

n in

itia

l

tem

pe

ratu

re.

It is t

he

n d

rop

pe

d in

to a

be

ake

r

co

nta

inin

g 0

.15

kg

of w

ate

r w

ith

an

in

itia

l

tem

pe

ratu

re o

f 2

1.0

°C

. T

he

bo

lt a

nd

th

e w

ate

r th

en

rea

ch

a f

ina

l te

mp

era

ture

of 2

5.0

°C.

If th

e m

eta

l h

as

�2

01

0 H

erb

ert

B. D

om

ing

o

a s

pe

cific

he

at ca

pa

city o

f 8

99

J/k

g-C

°, f

ind

the

in

itia

l te

mp

era

ture

of th

e m

eta

l.

Page 34: material. • To use temperature as a measure of hotness and … · 2020-04-08 · K. Heat and Temperature 1. Temperature & Thermal Equilibrium Thermometer • First, select any measurable

K. H

eat

an

d T

em

pera

ture

Ex

am

ple

7. (S

OL

N)

�2

01

0 H

erb

ert

B. D

om

ing

o

K. H

eat

an

d T

em

pera

ture

Ex

am

ple

7. (S

OL

N)

�2

01

0 H

erb

ert

B. D

om

ing

o

Page 35: material. • To use temperature as a measure of hotness and … · 2020-04-08 · K. Heat and Temperature 1. Temperature & Thermal Equilibrium Thermometer • First, select any measurable

K. H

eat

an

d T

em

pera

ture

Ex

am

ple

7. (S

OL

N)

�2

01

0 H

erb

ert

B. D

om

ing

o

K. H

eat

an

d T

em

pera

ture

Ca

lori

me

try

(no

ph

as

e c

ha

ng

e)

�2

01

0 H

erb

ert

B. D

om

ing

o

Page 36: material. • To use temperature as a measure of hotness and … · 2020-04-08 · K. Heat and Temperature 1. Temperature & Thermal Equilibrium Thermometer • First, select any measurable

K. H

eat

an

d T

em

pera

ture

Ex

am

ple

8. C

ha

ng

es

in

bo

th t

em

pe

ratu

re a

nd

ph

as

e

Ho

w m

uch

en

erg

y is r

em

ove

d w

he

n 1

0.0

g o

f w

ate

r is

co

ole

d f

rom

ste

am

at 1

33

.0°C

to

liq

uid

at 5

3.0

°C?

�2

01

0 H

erb

ert

B. D

om

ing

o

K. H

eat

an

d T

em

pera

ture

Ex

am

ple

8.

Ch

an

ge

s in

bo

th t

em

pe

ratu

re a

nd

ph

as

e

�2

01

0 H

erb

ert

B. D

om

ing

o

Page 37: material. • To use temperature as a measure of hotness and … · 2020-04-08 · K. Heat and Temperature 1. Temperature & Thermal Equilibrium Thermometer • First, select any measurable

K. H

eat

an

d T

em

pera

ture

Ex

am

ple

8. (S

OL

N)

�2

01

0 H

erb

ert

B. D

om

ing

o

K. H

eat

an

d T

em

pera

ture

Ex

am

ple

8. (S

OL

N)

�2

01

0 H

erb

ert

B. D

om

ing

o

Page 38: material. • To use temperature as a measure of hotness and … · 2020-04-08 · K. Heat and Temperature 1. Temperature & Thermal Equilibrium Thermometer • First, select any measurable

K. H

eat

an

d T

em

pera

ture

Ex

am

ple

8. (S

OL

N)

�2

01

0 H

erb

ert

B. D

om

ing

o

K. H

eat

an

d T

em

pera

ture

Ca

lori

me

try

(wit

h p

os

sib

le p

ha

se

ch

an

ge

)

�2

01

0 H

erb

ert

B. D

om

ing

o