Download “EARTH`S ENERGY“

“EARTH’S ENERGY“
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5.1) Electromagnetic Energy.
energy
is the ability to do work.
Everything that is done in the universe
involves the use or transfer of energy.
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There are two sources for Earth’s
heat energy.
1) Internal source
 heat from earth’s interior.
Comes from;
1 - remnant heat
2 - radioactive decay.
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2) External source
Comes from;
Insolation – energy from the sun.
(In/sol/ation) incoming solar
radiation.
This drives most Earth surface
processes.
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Electromagnetic Energy.
energy that is radiated (given off) by all
matter that is not at absolute zero.
absolute zero = the lowest possible
temperature.
0 Kelvin or -273oC.(-459.67F)
the higher the temperature, the greater the
amount of energy that is given off.
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Characteristics and Types of
Electromagnetic Energy.
• different types of electromagnetic energy
are distinguished by their wavelength.
• wavelength - the distance from one crest of
a wave to the next crest.
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diagram;
crest
one wavelength
|
|
trough
crest
|
|
one wavelength
trough
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Electromagnetic Spectrum
See ESRT p. 14
Short Wave Energy
High energy
Long Wave Energy
Low energy
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The electromagnetic spectrum
a model that shows all the types of
electromagnetic energy.
Visible light is the only portion of the
spectrum that we can see with our eyes.
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1) Which type of electromagnetic radiation
has the longest wavelength?
(1) ultraviolet
(2) gamma rays
(3) visible light
(4) radio waves
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2) Which graph best represents the relative
wavelengths of the different forms of
electromagnetic energy?
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3) Which color of the visible spectrum has
the shortest wavelength?
(1) violet
(2) blue
(3) yellow
(4) red
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4) In which list are the forms of
electromagnetic energy arranged in order
from longest to shortest wavelengths?
(1) gamma rays, x rays, ultraviolet rays,
visible light
(2) radio waves, infrared rays, visible light,
ultraviolet rays
(3) x rays, infrared rays, blue light, gamma
rays
(4) infrared rays, radio waves, blue light,
red light
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5) What is the basic difference between
ultraviolet, visible, and infrared radiation?
(1) half-life
(2) temperature
(3) wavelength
(4) wave velocity
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DATE
Main Ideas and Supporting Details
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There are three types of
spectrum.
1) continuous
 a continuous band of colors, with one color
blending into the next, the “real” rainbow.
 Produced by a glowing solid or liquid, or by a
highly compressed glowing gas.
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2) bright line (emission)
dark background with a series of thin
brightly colored lines.
Produced from a non-compressed gas.
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3) dark line (absorption)
a continuous spectrum with thin black
lines.
Produced from the sun’s light, where light
passes through a cooler gas.
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Interactions between
Electromagnetic Energy and an
Environment.
When electromagnetic waves strike an
object they may be….
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1) refracted
 bent.
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2) reflected
bounced off.
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3) scattered
refracted and/or reflected in various
directions.
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4) transmitted
passed through the material.
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5) absorbed
taken into the material.
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Surface Properties and
Absorption.
The characteristics of the surface of a
material will determine the amount of
electromagnetic energy that can be
absorbed.
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Characteristics
1) Color
dark color – absorbs well.
light color – absorbs poorly. (it
reflects energy)
2) Texture
rough surface – absorbs well.
smooth surface – absorbs poorly. (it
reflects energy)
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A material that absorbs
electromagnetic energy well will..
heat up quickly.
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A material that heats up quickly
will also..
radiate (gives off) energy well.
It will cool quickly
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5-2)
Transfer of Energy
Energy moves from a …
region of high concentration
(a source)
to a …
region of low concentration
(a sink).
SOURCE
SINK
(high)
(low)
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heat energy –
energy that is transferred from a
region of high temperature to a
region of lower temperature.
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Achieving Dynamic
Equilibrium
Heat will move from a ..
source to a sink until their energies
are equal.
Dynamic Equilibrium is achieved
when..
the amount of energy being gained is
equal to the amount of energy being
lost.
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3 Methods of Energy
Transfer
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1 - CONDUCTION
Heat energy is transferred from
atom to atom, when vibrating atoms
collide.
Conduction is most effective in
solids.
diagram:
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HOT
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DATE
Main Ideas and Supporting Details
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2 - CONVECTION
caused by differences in density.
warmer portions have a lower density
and rise.
cooler portions have a greater density
and sink.
only occurs in fluids;
gases.
liquids and
convection currents occur in;
– atmosphere, the hydrosphere, & below
the lithosphere.
Diagram:
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3 - RADIATION.
caused by electromagnetic waves.
no medium is needed to transfer
electromagnetic waves.
examples; sunlight warming the earth
or heating the inside of a car.
diagram;
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Diagram 1; Earth
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Energy travels
through space
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Diagram 2; Inside car
The inside is hotter
than the
temperature outside.
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5-3) Transformation of
Energy
changing one type of energy into
another.
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Examples;
1) friction –
 kinetic energy is transformed into
heat energy.
 glacier flowing down a valley.
2) waves
 Wind blowing on the ocean.
 energy from atmosphere to
hydrosphere.
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Transformations of
Mechanical Energy
mechanical energy –
potential + kinetic energy.
the energy of an object that is not
related to the motion of atoms.
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kinetic energy energy of motion.
the faster an object moves, the
greater its kinetic energy.
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potential energy energy of position, or phase. (“stored
energy”)
 the higher an object is above the
center of the earth, the greater its
potential energy.
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Example;
Waterfall
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Water at the top of
a waterfall has
potential energy.
as the water falls,
some of its
potential energy
becomes kinetic
energy.
diagram
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Capture this energy…
(Build your own waterfall)
Hydroelectric
Height 726
River view of the eventual
site of Hoover Dam, circa
1904
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Transformation of
Electromagnetic Energy
Electromagnetic energy absorbed by
an object is reradiated at a longer
wavelength.
high temp. emits short wavelength.
lower temp emits longer wavelength.
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Earth example;
Short wavelength radiation from the
sun (insolation) is absorbed and …
….reradiated as longer wavelength
radiation (infrared) from the earth.
diagram
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Long wave from Earth
Short wave from sun.
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Temperature
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temperature
is a measure of the average kinetic
energy of the particles of a body of
matter.
One molecule
Atoms in a gas
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The instrument that is
used to measure
temperature is a ….
thermometer
Mercury thermometer
Galileo thermometer
digital
IR thermometer
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There are three different
temperature scales…




Fahrenheit
Celsius
Kelvin – do not use degree sign;
absolute zero is 0K
use ESRT to do conversions
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200 oF
=
93
140 oF =
60oC
46 oF
=
8
5 oF
=
-15
-13 oF
=
-25 oC
o
C =
oC
oC
367 K
=
333
=
280 K
=
258
=
248 K
K
K
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Heat and Thermal Energy
FYI
Heat – is the transfer or
flow of energy from a
Hot object to one that is
cooler.
Thermal energy – When
you feel a warm object
You are actually feeling
thermal energy – the
movement of molecules
that make up the object.
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Heat energy is measured in
a unit called a joule.
4.184 joules = 1 calorie
1 calorie
• heat needed to raise one gram of
liquid water by one degree Celsius.
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Different materials heat up at
different rates.
Specific Heat
• heat needed to raise one gram of any
substance one degree Celsius.
• or…specific heat can be defined as
–the resistance a material presents
to heating up or cooling off.
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Liquid water has the highest specific
heat of all naturally occurring
substances. see Earth Science Reference Tables.
For a 1 gram sample..
4.18 J raises temp 1oC
4.18 J raises temp 6932oC
Heat Energy and Changes of
State
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Melting
Solid to liquid.
(ice cubes melting)
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melting titanium
Solidification (freezing)
Liquid to solid (water freezing)
Toronto
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Evaporation (vaporization)
Liquid to gas (boiling water)
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Condensation
Gas to liquid
(rain, mirror in bathroom)
dew
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Sublimation
Solid to gas
dry ice
(decrease in snowpack)
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Changes of State (phase)
solid
liquid
gas
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Changes of State (phase)
HEAT IS RELEASED
precipitation
solidification
condensation
solid
334 J/g
melting
liquid
2260 J/g
gas
vaporization
sublimation
HEAT IS ABSORBED
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Stored Heat and Changes of
States
During a change of state,
heat added does not change the
temperature.
The added heat energy is
being converted to a kind of
potential energy, or stored heat.
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Draw and label diagram;
Heating of Water
gas
evaporation
condensation
100oC
temperature
liquid
melting
0oC
freezing
solid
-100oC
time
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Earth's Energy Supply
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1 - Solar Energy
Of all the types of electromagnetic
radiation from the sun, the one with
the greatest intensity is …
visible light.
Solar energy is produced by …
nuclear fusion.
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2 - Earth's own Energy
1 - heat that remains from when the
Earth formed.
2 - nuclear decay of radioactive
materials.
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