Download Approximate Wavelength

Do Now:
How many frames are in a Pixar animated movie such as The
Incredibles? [What would you need to know? Explain your
reasoning and show your work.]
Avg. Length * Seconds/Hour * Frames/Second = # of Frames
1. 5 hours
*
3600 s / hr
*
24 frames/s
= 129,600 frames
The Electromagnetic Spectrum
& Types of Solar Energy
Essential Questions
 What is the electromagnetic spectrum, how does it
behave, and how is it related to temperature?
 What is active solar energy and how can it be used?
 What is passive solar energy and how can it be used?
The Electromagnetic Spectrum
 The star at the center of our planetary system, our sun, is named
Sol. That’s why our system is called the Solar system.
 Our sun averages about 5800K in temperature and emits energy in
the form of electromagnetic waves.
 The distance between peaks in an electromagnetic wave is called
the wavelength. Different wavelengths of electromagnetic radiation
are released at different temperatures.
Visible
light is an
example of
So are Gamma
Rays…
electromagnetic waves.
The Electromagnetic Spectrum
Have
Do
you
think
noticed
that
that
it’s
filament
convenient
light
bulbs,
that
radiant
our
eyes
heaters,
have
and
The
chart
below
shows
the
variation
in
peak
wavelength
Do you
you
remember
themerely
average
temperature
of
our
sun?
What
ceramic
evolved
stovetops
topeak
seeobject
in
the
all as
seem
visible
spectrum?
glow
as they
heat
up?
You4500K
will
emitted
by
an
the to
temperature
increases
from
would its
wavelength
be?
What
color
of light
would
be
notice
their color change from red, to orange, to yellow as they
to
7500K.
brightest?
get hotter…emitting all colors of the visible spectrum, the hotter
they get.
• Sol is approximately
5800K
• Green light is the peak
wavelength
The Visible Spectrum
 What is the Visible Spectrum?
The
Much
All of
visible
of
this
the
energy
spectrum
energy
travels
from
is that
as
part
our
waves
sun
of and
the
is emitted
electromagnetic
behavesinaccording
the
spectrum
visible
to certain
range.
that
physical
is
There
visible
principles.
areto
the
alsohuman
significant
eye…from
amounts
about
in
390
the infrared
nm to 750
andnm.
ultraviolet
ranges as well.
How Does the
Color/Wavelength of Light
Affect PV Efficiency?
Test 5-8 colors using different
backgrounds on PowerPoint Slides
 Purple
 Blue
 Green
 Yellow
 Orange
 Red
 White
How Does Radiant Energy Behave?
Electromagnetic Energy travels in waves; some waves are
longer than others (i.e. some waves have different
wavelengths).
Reflectance
(R),
Absorptance
(A),
Blue
light
has
shorter
waves
Not all
materials
behave
theexplain
same
Using
what
you’ve
learned,
and
(T)
are
physical
than
the
of of
the
visible
way Transmittance
at
wavelengths.
For
why
theallrest
inside
car
gets
hot
on a
properties
of
materials.
spectrum,
so it is
scattered visible
example,
glass
transmits
sunny
day?
more
by molecules
in the and
light but
reflects infrared
R
+T+A=
1That is why our
atmosphere.
ultraviolet
wavelengths.
sky appears blue!
Infrared
Waves
travel
in straight
lines unless interrupted; then they
In other
words,
radiant energy
can
be… at a surface is either
arriving
•reflected
Reflected
(liketransmitted
with a mirror)
away,
•through,
Absorbed
(like with by
asphalt
or absorbed
that on a hot day)
•surface.
Transmitted (bent, but allowed to pass through, like with
water or a prism)
Types of Solar Energy
1. Passive
2. Active
Types of Solar Energy
Passive
The capture and use of solar
energy w/o the aid of any
moving mechanical systems.
Types of Solar Energy
Active
The capture and use of solar
energy and its conversion to heat
or electricity using mechanical or
chemical systems or effects
What’s Coming Up?
 Passive Solar Energy
 Active Solar Energy
 Power Transmission
 Impacts on Environment/Society