at · 2016. 6. 24. · conduction and convection Gizmo There are TWO flasks: one blue and one...
16
Energy Likes to Move If there is a temperature difference in a system, heat will naturally move from high to low temperatures. The place you find the higher temperature is the heat source. The area where the temperature is lower is the heat sink. When examining systems, scientists measure a number called the temperature gradient. The gradient is the change in temperature divided by the distance. The units are degrees per centimeter. If the temperature drops over a specific distance, the gradient is a negative value. If the temperature goes up, the gradient has a positive value. The greater the gradient, the more energy will be exchanged. Ever Hear of Convection Ovens? Convection is the way heat is transferred from one area to another when there is a "bulk movement of matter." It is the movement of huge amounts of material, taking the heat from one area and placing it in another. Warm air rises and cold air replaces it. The heat has moved. It is the transfer of heat by motion of objects. Convection occurs when an area of hot water rises to the top of a pot and gives off energy. Another example is warm air in the atmosphere rising and giving off energy. They are all examples of convection. The thing to remember is that objects change position. Radiating Energy When the transfer of energy happens by radiation, there is no conductive medium (such as in space). That lack of medium means there is no matter there for the heat to pass through. Radiation is the energy carried by electromagnetic waves (light). Those waves could be radio waves, infrared, visible light, UV, or Gamma rays. Heat radiation is usually found in the infrared sections of the EM spectrum. If the temperature of an object doubles (in Kelvin), the thermal radiation increases 16 times. Therefore, if it goes up four times, it increases to 32 times the original level. Scientists have also discovered that objects that are good at giving off thermal radiation are also good at absorbing the same energy. Usually the amount of radiation given off by an object depends on the temperature. The rate at which you absorb the energy depends on the energy of the objects and molecules surrounding you. Conducting Energy and Heat Conduction is a situation where the heat source and heat sink are connected by matter. As we discussed before, the heat flows from the source down the temperature gradient to the sink. It is different from convection because there is no movement of large amounts of matter, and the transfers are through collisions. The source and the sink are connected. If you touch an ice cream cone, the ice cream heats up because you are a warmer body. If you lie on a hot sidewalk, the energy moves directly to your body by conduction. When scientists studied good thermal radiators, they discovered that good thermal conductors are also good at conducting electricity. So when you think of a good thermal conductor, think about copper, silver, gold, and platinum.
Transcript of at · 2016. 6. 24. · conduction and convection Gizmo There are TWO flasks: one blue and one...
En
erg
y L
ike
s to
Mo
ve
If
th
ere
is a
te
mp
era
ture
diffe
ren
ce
in a
syst
em
, h
ea
t w
ill n
atu
rally
mo
ve
fro
m h
igh
to
low
tem
pe
ratu
res.
Th
e p
lac
e y
ou
fin
d t
he
hig
he
r te
mp
era
ture
is t
he
he
at
sou
rce
. Th
e a
rea
wh
ere
th
e
tem
pe
ratu
re is
lo
we
r is
th
e h
ea
t si
nk
. W
he
n e
xa
min
ing
syst
em
s, s
cie
ntist
s m
ea
sure
a n
um
be
r
ca
lled
th
e t
em
pe
ratu
re g
rad
ien
t. T
he
gra
die
nt
is t
he
ch
an
ge
in t
em
pe
ratu
re d
ivid
ed
by t
he
dis
tan
ce
. Th
e u
nits
are
de
gre
es
pe
r c
en
tim
ete
r. If
the
te
mp
era
ture
dro
ps
ove
r a
sp
ec
ific
dis
tan
ce
,
the
gra
die
nt
is a
ne
ga
tiv
e v
alu
e. If
th
e t
em
pe
ratu
re g
oe
s u
p, th
e g
rad
ien
t h
as
a p
osi
tiv
e v
alu
e.
The
gre
ate
r th
e g
rad
ien
t, t
he
mo
re e
ne
rgy w
ill b
e e
xc
ha
ng
ed
.
Ev
er
He
ar
of
Co
nv
ec
tio
n O
ve
ns?
C
on
ve
ctio
n is
th
e w
ay h
ea
t is
tra
nsf
err
ed
fro
m o
ne
are
a t
o a
no
the
r w
he
n t
he
re is
a "
bu
lk
mo
ve
me
nt
of
ma
tte
r."
It is
th
e m
ove
me
nt
of
hu
ge
am
ou
nts
of
ma
teria
l, ta
kin
g t
he
he
at
fro
m o
ne
are
a a
nd
pla
cin
g it
in a
no
the
r. W
arm
air r
ise
s a
nd
co
ld a
ir r
ep
lac
es
it. Th
e h
ea
t h
as
mo
ve
d. It
is
the
tra
nsf
er
of
he
at
by m
otio
n o
f o
bje
cts
. C
on
ve
ctio
n o
cc
urs
wh
en
an
are
a o
f h
ot
wa
ter
rise
s to
the
to
p o
f a
po
t a
nd
giv
es
off
en
erg
y.
An
oth
er
exa
mp
le is
wa
rm a
ir in
th
e a
tmo
sph
ere
ris
ing
an
d
giv
ing
off
en
erg
y. Th
ey a
re a
ll e
xa
mp
les
of
co
nv
ec
tio
n. Th
e t
hin
g t
o r
em
em
be
r is
th
at
ob
jec
ts
ch
an
ge
po
sitio
n.
Ra
dia
tin
g E
ne
rgy
Wh
en
th
e t
ran
sfe
r o
f e
ne
rgy h
ap
pe
ns
by ra
dia
tio
n, th
ere
is n
o c
on
du
ctiv
e m
ed
ium
(su
ch
as
in
spa
ce
). T
ha
t la
ck o
f m
ed
ium
me
an
s th
ere
is n
o m
att
er
the
re f
or
the
he
at
to p
ass
th
rou
gh
.
Ra
dia
tio
n is
th
e e
ne
rgy c
arr
ied
by e
lec
tro
ma
gn
etic
wa
ve
s (l
igh
t). Th
ose
wa
ve
s c
ou
ld b
e r
ad
io
wa
ve
s, in
fra
red
, v
isib
le lig
ht,
UV
, o
r G
am
ma
ra
ys.
He
at
rad
iatio
n is
usu
ally
fo
un
d in
th
e in
fra
red
sec
tio
ns
of
the
EM
sp
ec
tru
m. If
th
e t
em
pe
ratu
re o
f a
n o
bje
ct
do
ub
les
(in
Ke
lvin
), t
he
th
erm
al
rad
iatio
n in
cre
ase
s 1
6 t
ime
s. T
he
refo
re, if it
go
es
up
fo
ur
tim
es,
it in
cre
ase
s to
32
tim
es
the
orig
ina
l
lev
el.
Sc
ien
tist
s h
av
e a
lso
dis
co
ve
red
th
at
ob
jec
ts t
ha
t a
re g
oo
d a
t g
ivin
g o
ff t
he
rma
l ra
dia
tio
n a
re a
lso
go
od
at
ab
sorb
ing
th
e s
am
e e
ne
rgy. U
sua
lly t
he
am
ou
nt
of
rad
iatio
n g
ive
n o
ff b
y a
n o
bje
ct
de
pe
nd
s o
n t
he
te
mp
era
ture
. Th
e r
ate
at
wh
ich
yo
u a
bso
rb t
he
en
erg
y d
ep
en
ds
on
th
e e
ne
rgy
of
the
ob
jec
ts a
nd
mo
lec
ule
s su
rro
un
din
g y
ou
.
Co
nd
uc
tin
g E
ne
rgy a
nd
He
at
Co
nd
uc
tio
n is
a s
itu
atio
n w
he
re t
he
he
at
sou
rce
an
d h
ea
t si
nk a
re c
on
ne
cte
d b
y m
att
er.
As
we
dis
cu
sse
d b
efo
re, th
e h
ea
t flo
ws
fro
m t
he
so
urc
e d
ow
n t
he
te
mp
era
ture
gra
die
nt
to t
he
sin
k. It
is
diffe
ren
t fr
om
co
nv
ec
tio
n b
ec
au
se t
he
re is
no
mo
ve
me
nt
of
larg
e a
mo
un
ts o
f m
att
er,
an
d t
he
tra
nsf
ers
are
th
rou
gh
co
llisi
on
s. T
he
so
urc
e a
nd
th
e s
ink a
re c
on
ne
cte
d.
If y
ou
to
uc
h a
n ic
e c
rea
m c
on
e, th
e ic
e c
rea
m h
ea
ts u
p b
ec
au
se y
ou
are
a w
arm
er
bo
dy. If
yo
u
lie o
n a
ho
t si
de
wa
lk, th
e e
ne
rgy m
ove
s d
ire
ctl
y t
o y
ou
r b
od
y b
y c
on
du
ctio
n.
Wh
en
sc
ien
tist
s
stu
die
d g
oo
d t
he
rma
l ra
dia
tors
, th
ey d
isc
ov
ere
d t
ha
t g
oo
d t
he
rma
l c
on
du
cto
rs a
re a
lso
go
od
at
co
nd
uc
tin
g e
lec
tric
ity
. So
wh
en
yo
u t
hin
k o
f a
go
od
th
erm
al c
on
du
cto
r, t
hin
k a
bo
ut
co
pp
er,
silv
er,
go
ld, a
nd
pla
tin
um
.
Ge
ttin
g H
ott
er
= G
ett
ing
Big
ge
r N
ow
yo
u n
ee
d t
o t
hin
k a
bo
ut
sta
tes
of
ma
tte
r a
littl
e b
it.
We
'll s
tart
with
ga
ses.
Th
e id
ea
be
hin
d
the
rma
l e
xp
an
sio
n is
th
at
ga
ses
exp
an
d a
s th
e t
em
pe
ratu
re in
cre
ase
s. If
yo
u h
av
e a
ba
lloo
n a
nd
yo
u h
ea
t u
p t
he
co
nte
nts
, th
e b
allo
on
will
ge
t la
rge
r. S
cie
ntist
s u
se t
he
te
rm id
ea
l g
as
law
to
de
scrib
e t
his
ac
tiv
ity.
Liq
uid
s e
xp
an
d a
nd
co
ntr
ac
t, t
oo
, b
ut
the
re is
a lo
t le
ss c
ha
ng
e t
ha
n in
ga
ses.
Sc
ien
tist
s sa
y t
he
y
ha
ve
a s
ma
ller
the
rma
l exp
an
sio
n c
oe
ffic
ien
t. A
s yo
u c
an
pro
ba
bly
fig
ure
ou
t, s
olid
s e
xp
an
d a
nd
co
ntr
ac
t th
e le
ast
of
all
the
sta
tes
of
ma
tte
r. T
he
exp
an
sio
n c
oe
ffic
ien
t is
diffe
ren
t fo
r e
ac
h p
iec
e
of
ma
tte
r. It
is a
un
iqu
e v
alu
e, ju
st lik
e s
pe
cific
he
at
ca
pa
city
. Tw
o e
xa
mp
les
of
co
eff
icie
nts
are
air
at
.00
36
7 a
nd
alc
oh
ol a
t .0
00
11
2.
Thin
gs
Sh
rin
k W
he
n T
he
y g
et
Co
ld
The
op
po
site
of
exp
an
sio
n is
co
ntr
ac
tio
n. If
th
ing
s e
xp
an
d w
ith
th
e a
dd
itio
n o
f h
ea
t, it
ma
ke
s
sen
se t
ha
t th
ey c
on
tra
ct
wh
en
he
at
is r
em
ov
ed
. If
yo
u r
em
ov
e e
no
ug
h h
ea
t fr
om
a g
as
it w
ill
be
co
me
a liq
uid
. Liq
uid
s c
an
tu
rn in
to s
olid
s w
ith
fu
rth
er
co
olin
g. W
ha
t h
ap
pe
ns
wh
en
yo
u
rem
ove
alm
ost
all
of
the
en
erg
y f
rom
a s
yst
em
? S
cie
ntist
s u
se t
he
te
rms
ab
solu
te z
ero
to
de
scrib
e
a s
yst
em
th
at
ha
s n
o k
ine
tic
en
erg
y. W
he
n t
he
re is
no
kin
etic
en
erg
y in
a s
yst
em
, a
ll m
ole
cu
lar
mo
tio
n s
top
s. It
see
ms
tha
t e
ve
n t
he
ato
ms
be
gin
to
me
rge
at
the
se lo
w t
em
pe
ratu
res.
Ph
ysi
cis
ts
ha
ve
re
ce
ntly c
rea
ted
th
e B
ose
-Ein
ste
in s
tate
of
ma
tte
r th
at
ha
s a
sm
all
gro
up
of
ato
ms
with
ne
arly a
ll o
f th
e k
ine
tic
en
erg
y t
ake
n o
ut
of
the
syst
em
.
1. 2.
3. 4.
Read It!
Read It!
Read It! Read It!
Heat moves from a ____________
temperature to a _______________
temperature.
A. Higher; higher
B. Lower; higher
C. Higher; lower
D. Lower; lower
Warm air __________ and cool
air ____________.
A. Rises; remains the same
B. Sinks; rises
C. Rises; sinks
D. Remains the same; sinks
Type of heat transfer that can occur
through empty space.
A. conduction
B. convection
C. radiation
D. transmission
Heat transfer that occurs between items
that are touching.
A. conduction
B. convection
C. radiation
D. transmission
1. 2.
3. 4.
Watch It!
Watch It!
Watch It! Watch It!
Go to the following link and watch the
study jams video:
http://tinyurl.com/29qzmym
Answer the questions on Task
Cards 2-7 on your lab sheet in
the Watch It! Section.
What is heat?
A. Thermal Energy
B. Temperature
C. Electricity
D. Electromagnetic energy
Which of the following explains
the process of radiation?
A. When heat gets transferred through
objects that are touching.
B. When the measurement of heat in
the atmosphere goes down.
C. When heat gets transferred through
electromagnetic waves that move
through space.
D. When heat gets transferred through
a liquid or a gas.
How does heat transfer through
conduction?
A. From the warm object to the
cool object
B. From the cool object to the
warm object
C. From the air to the cool object
D. From the warm object into the
air
5. 6.
7
Watch It!
Watch It!
Watch It!
Why does the water in a swimming pool
stay cool on a hot, sunny day?
A. Because radiation has no effect on
water
B. Because of convection
C. Because the pool is a good insulator
D. Because the rays of the sun are
reflected off of the surface of the
water.
Which method transfers heat through
a liquid or a gas?
A. conduction
B. convection
C. radiation
D. transmission
What is the difference between a conductor
and an insulator?
A. An insulator lets heat pass through it
easily; a conductor does not let heat
pass through it easily.
B. A conductor is unaffected by heat and
an insulator is greatly affected by heat.
C. A conductor lets heat pass through it
easily; an insulator does not let heat
pass through it easily.
1.
Organize It!
Sort the cards into the three
categories; conduction,
convection, or radiation. Make
sure your teacher checks and
initials your lab sheet.
1. 2.
3. 4.
Explore It!
Explore It!
Explore It! Explore It!
Go to: https://
www.explorelearning.com/
Find the
conduction
and
convection
Gizmo
There are TWO flasks: one blue and
one yellow.
~Select COPPER & Select SOLID
CHUNK
~Use the sliders to make one flask
hotter than the other.
~Click Play
Answer the questions on the LAB
SHEET
Click Reset
Set the Initial temperature of the top
flask to 95 °C and the bottom flask
to 5 °C.
Observe: Run the Gizmo twice – once
with a Solid chunk of Copper
separating the liquids, and once
with a Solid chunk of Stone.
Experiment: Experiment with all
six Solid chunks. For
each, click Fast forward
and then, after about 500
seconds, Pause
Record the temperature of each
flask.
Fill in the data table on your lab
sheet under Explore It!
1. 2.
3. 4.
Assess It!
Assess It!
Assess It! Assess It!
The transfer of heat through
currents is…
A. Conduction
B. Convection
C. Radiation
D. Transformation
A thermos bottle keeps warm liquids warm
and cold liquids cold. A thermos bottle
must be made from a good
A. heat conduction material
B. heat insulation material
C. heat expanding material
D. heat contracting material
When a metal spoon with a temperature of
20oC is placed into a cup of water with a
temperature of 90oC the spoon will heat up.
This is an example of:
A. convection
B. radiation
C. conduction
D. insulation
Materials through which heat can
flow easily are called
A. insulators
B. radiators
C. transformers
D. conductors
5. 6.
7. 8.
Assess It! Assess It!
Assess It! Assess It!
Two jars are placed inside an insulated box
(together). One contains hot soup and the
other contains ice water. What will happen to
the two liquids?
A. Both the hot soup and the ice water will
gain heat.
B. Both the hot soup and the ice water will
lose heat.
C. The hot soup will gain heat and the ice
water will lose heat.
D. The hot soup will lose heat and the ice
water will gain heat.
When cooking macaroni and cheese, the
noodles float up to the top and sink back
down. This is an example of:
A. convection
B. conduction
C. radiation
D. insulation
During a house fire, the smoke and
flames rise up, but the air down
near the floor is cooler and less
smoky. This is an example of:
A. conduction
B. convection
C. radiation
D. insulation
Four different-colored blocks are
placed outside in bright sunlight. The
blocks are identical except for color.
The diagram below shows the amount
of light reflected from each block.
Which block
would heat up
the fastest?
A. Block 1
B. Block 2
C. Block 3
D. Block 4
1. 2.
Research It!
Research It!
Write It!
Heat is transferred by
radiation from the sun to the
Earth. Why do coastal
(located near ocean)
communities have cooler
summers and warmer
winters?
What type of heat transfer
causes the movement of
Earth’s tectonic plates?
How?
What type of heat
transfer is involved in
cooking an egg.
Describe the heat transfer
processes from start to finish.
Write It!
You took a can of soda out
of the fridge. After holding it
for a few minutes, what has
happened to the
temperature of the can? What has
happened to the temperature of
your hand? Why? Describe the
process(es) that have taken place.
1. 2.
1. 2.
Illustrate It!
Illustrate It!
Draw a diagram of radiation.
Use squiggly red arrows to
show the direction the thermal
energy is moving.
3. 1.
Illustrate It!
BONUS
Write a story about thermal
energy’s long journey from the
sun. How long does it take light
and heat to reach Earth? What
happens during this journey?
Draw a diagram of
conduction. Use red arrows to
show the direction the thermal
is moving.
Draw a diagram of
convection. Use red arrows to
represent high temperature
and blue arrows to represent a
low temperature.
Through Space
Movement through a
fluid
Cooler downstairs than
upstairs
Collision of atoms
Direct contact
Name: ______________________________ Class:_____________ Date:__________
Input Stations
Explore It!
Task Card 2:
Use the sliders to make one flask hotter than the other. Click play.
What happens? _________________________________________________
_________________________________________________________________
Select the DATA tab and look at the graph. What do the blue curve
and the yellow curve represent?
A. The blue curve represents ________________________________
B. The yellow curve represents _______________________________
C. What is the final temperature of the top flask? ___________________
D. What is the final temperature of the bottom flask? _______________
Task Card 3:
Observe: Run the Gizmo twice – once with a Solid chunk of Copper
separating the liquids, and once with a Solid chunk of Stone.
Watch how quickly the temperatures of the liquids change in
both cases. (Note: This solid chunk keeps the liquids from mixing.)
Form hypothesis: A conductor allows heat to flow easily, while an
insulator resists heat flow. In general, what kinds of materials do
you think are good conductors?
_________________________________
Predict: Of the six substances in the Gizmo, which ones will allow the
fastest temperature change in the two flasks? ________________
Task Card 4:
Analyze: What substances conducted heat the best? _____________
______________________________________________________________
How do you know? __________________________________________
______________________________________________________________
Draw conclusions: What do the best conductors have in common?
_____________________________________________________
_____________________________________________________
Read It!
Watch It!
___________4.
___________5.
___________6.
___________7.
___________1. ___________2. ___________3. ___________4.
___________2.
___________3.
Connection
Initial
temp.
(top flask)
Initial temp.
(bottom
flask)
500 sec.
temp.
(top
flask)
500 sec.
temp.
(bottom
flask)
Solid copper 95 °C 5 °C
Solid gold 95 °C 5 °C
Solid lead 95 °C 5 °C
Solid stone 95 °C 5 °C
Solid glass 95 °C 5 °C
Solid rubber 95 °C 5 °C
Output Stations:
Write It!
Assess It!
Output Stations
Illustrate It
Organize It!
Reflection: How did you do? What did you find easy? What
mistakes did you make?
Task Card 2:
Teacher Initials:
Task Card 1:
___________1. ___________3.
___________2. ___________4.
____________5.
____________6.
____________7.
____________8.
Task Card 1: Task Card 2:
Task Card 3: Task Card 4:
