system storage

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inflow
inflow
outflow
system storage
system storage
outflow
outflow
inflow
system storage
system storage
inflow
outflow
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12
983
875
System storage 10
System storage 10
System storage 10
-14
-877
-985
flows
Small
large
large
storage
Small
small
large
change
-
2
-
2
-
2
4
4
Storage 30
10
-1
-7
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Energy transferred Q (joules J)
Rate of energy transfer Energy flux ? or power P
(watts W)
?Q/?t ? P
Amount of energy ?Q (J) crossing a surface per
time interval ?t (s)
Energy flux density ? (W.m-2)
Amount of energy ?Q (J) crossing a surface per
area A (m2) per time interval ?t (s)
?? P / A ? / A
A (m2)
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?net ?global asoil ?global ?atm asoil
?atm ?soil
?soil lt 0
?global gt 0
asoil ?global lt 0
?atm gt 0
asoil ?atm lt 0
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hot, sunny, dry day air temperature 24 C
?U m c ?T A ?t (?net radiation
?cond ?conv ?latent) Pint ?t
?net radiation lt 0
?latent lt 0 Evaporation of sweat
Pint gt 0
?conv lt 0
What would happen on a very humid day when air
temperature soared above 37 C ?
?cond lt 0
What will happen to the chickens on a hot humid
day?
Skin / Surface temperature 34 C
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0.050 0.002 mm
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NIGHT
NIGHT
QLout
QLin
QLin
QLin
QR
QLin
Radiation budget
Energy Balance
DAY
DAY
QE
QLout
QR
QH
QSout
QLin
QSin
QB
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leaf aleaf tleaf ?leaf Tleaf
Long wave-length
Short wave-length
?global
?leaf ? Tleaf4
?Tatm4
aleaf ?global
(1- ?leaf)?Tatm4
Top leaf
Bottom leaf
tleaf ?global
aleaf asoil ?global
(1-?leaf)??soil?Tsoil4
?soil?Tsoil4
asoil ?global
?leaf ? Tleaf4
Soil asoil ?soil Tsoil
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?short wave rad (1 -aleaf - tleaf - aleaf
asoil asoil )?global
Short-Wave global
reflected by soil
incident global rad
reflected by soil then leaf
transmitted by leaf
reflected by leaf
?long wave rad gain ?leaf (?Tatm4 ?soil
?Tsoil4)
Long wave gain
radiation from atmosphere
radiation from soil
?soil long wave loss - 2 ?leaf ? Tleaf4 - (1 -
?leaf) (?Tatm4 ?soil ?Tsoil4)
Long Wave Loss
radiation emitted by leaf
reflected by leaf
?rad (1 -aleaf - tleaf - aleaf asoil
asoil )?global
(2?leaf - 1)(? Tatm4 ?soil?Tsoil4) - 2
?leaf ? Tleaf4
Radiation balance
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Inflow rate (input flux)
area
Rate of change of energy storage in the system
Outflow rate (output flux)
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container
loop of thread
pure water
water detergent
Shaded area here is greater than shaded area here
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container
matches
detergent added
becomes
pure water
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This end is repelled by water molecules
hydrophobic and is attracted to oils, fats
lipiphilic
This end is attracted to water
molecules hydrophilic
O
-
O
H
C
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water
grease
detergent added
stirred
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Bond broken by rotation
-
Water is a polar molecule
Rotation of molecule due to torque from
oscillating electric field of microwave
radiation
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h
dyed water
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angle of contact ?
tangent line
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F
DL
Area, A
L
q
F
Stress F / A strain q DL / L
q is small
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Frictional force due to grip on ground
Frictional opposing motion
X
10 N
- 10 N
Sum of horizontal forces -10 N 10 N 0 N

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X
Frictional opposing motion
20 N
- 10 N
Sum of horizontal forces -10 N 20 N 10 N
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Guinea pig G
Y
FPG
Ground G
FPE
FEP
FGP - FPG
FGP
Earth E
FPE force on Pig by Earth first subscript
represents the system
FEG - FGE
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F
Stress ?? F / A
Strain ? ?L / L
L
A
?L
F
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L ? L ?L
Stress S F / A
w ? w - ?L
A h w
F
h ? h - ?h
Strain e ?L / L
L ?L
w
L
h
F
?h/h ?w/w - ? e -? (?L/L)
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Stress p
Strain - ?V/ V
(the significance of the
minus sign is that the
volume decreases as the
pressure increases)
p
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Y
P
J
stress
strain
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a. I shape beam
b. Tube shape beam
c. Solid beam
d. Solid beam
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F
F
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sliding
rolling
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Fig. 13 Centre of mass
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Fig. 14 Free object
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Fig. 18 When the centre of mass is within the
bounded area of the supports the
car is in equilibrium. When the centre of mass is
outside the support base, it will
tip over.
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A
R small
B
C
V
A
Potentiometer (pot) Variable resistance
Pot Load R
Solar panel
B
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Areas with above average rainfall
1951
1950
Sea surface temp warmer than normal
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arid
Sub- humid
Semi- arid
Peri-arid
1911 - 1940
1881 - 1910
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1.6
1.4
Little ice age
1.2
1.0
Temperature fluctuation / C
0.8
0.6
0.4
0.2
0.0
900
1100
1300
1500
1700
1900
year
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Block vibrates up and down
Seat mass m
x
F
Equilibrium position x 0
Spring constant k
support
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Resonance peak
Amplitude of
the steady state
oscillation
fo
driving frequency
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Pos charged area
Neg charged area
NEG Pos charged area
Pos charged area
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