Falcon Focus
• (8-5.6) According to inertia, a moving object, if no forces act on it, will
____.
• A. eventually come to rest
• B. eventually change direction
• C. slow down but never completely stop
• D. remain in motion
•
• (8-5.6) A book sliding across a floor eventually comes to rest because ___.
•
• A. there are no forces acting on it
• B. there are outside forces acting on it
• C. of balanced forces
• D. of the mass of the book
Essential Question
• (8-5.5) What are the difference between
balance an unbalance forces? Give an
example of each.
Waves 8-6.8
Electromagnetic
Waves
Electromagnetic Waves
• Transverse waves without a medium!
• (They can travel through empty space)
• Electromagnetic waves travel VERY
FAST – around 300,000 kilometres per
second (the speed of light).
At this speed they can go
around the world 8 times
in one second.
Electromagnetic Spectrum
• Electromagnetic waves have a wide range of
wavelengths. The entire range of
wavelengths is called the electromagnetic
spectrum. The relationship between the
wavelength and energy of waves in various
parts of the electromagnetic spectrum can be
shown as follows:
Notice the wavelength is
long (Radio waves) and gets shorter (Gamma Rays)
Electromagnetic Spectrum
RADIO WAVES
• Have the longest
wavelengths and
lowest frequencies
of all the
electromagnetic
waves.
MRI
(MAGNETIC RESONACE IMAGING)
Uses Short wave radio waves with a magnet
to create an image.
MICROWAVES
• Have the shortest
wavelengths and
the highest
frequency of the
radio waves.
Used in microwave
ovens.
• Waves transfer
energy to the water
in the food causing
them to vibrate
which in turn
transfers energy in
the form of heat to
the food.
Visible Light
• Visible Light Is the range of electromagnetic
waves that can be detected by the human
eye.
• The entire range of visible light is called the
visible light spectrum (ROY G BIV)
• The wavelengths of visible light are in the
middle range of wavelengths/frequencies of
electromagnetic waves
• The longer the wavelength, the lower the
energy of the wave
The Human Eye and Visible Light
• The human eye reacts to different energies and
frequencies of light so that different colors are
seen
• Higher frequencies (shorter wavelengths) are
perceived as colors toward the blue-violet range
and have higher energy
• Lower frequencies (longer wavelengths) are
perceived as colors toward the orange-red range
and have lower energy
VISIBLE LIGHT
• Shorter wavelength and
higher frequency than
infrared rays.
• Electromagnetic waves we
can see.
• Longest wavelength= red
light
• Shortest wavelength= violet
(purple) light
Infrared Radiation
• Infrared Waves (heat)Is the range of
electromagnetic waves with frequencies lower
than red on the visible spectrum, thereby having
longer wavelengths and less energy than red
wavelengths
• All objects emit infrared radiation, and hotter
objects emit more infrared radiation than cooler
objects
• Heat energy is transmitted by infrared radiation
• When objects absorb infrared radiation, they
become warmer
Thermogram—a picture that shows regions of different
temperatures in the body. Temperatures are calculated by the
amount of infrared radiation given off.
•Therefore people give off
infrared rays.
•Heat lamps give off infrared
waves.
Ultraviolet Radiation
• Ultraviolet Radiation Is the range of
electromagnetic waves with frequencies
higher than violet on the visible spectrum,
thereby having shorter wavelengths and more
energy than violet wavelengths
• Because of the high energy of ultraviolet
radiation, too much exposure is damaging to
the eyes and skin
• Used to kill
bacteria.
(Sterilization of
equipment)
• Too much can cause skin cancer.
• Use sun block to protect against (UV
rays)
• Causes your
skin to produce
vitamin D
(good for teeth
and bones)
X- RAYS
• Shorter
wavelength and
higher frequency
than UV-rays
• Carry a great
amount of energy
• Can penetrate
most matter.
Bones and teeth absorb x-rays. (The light part of an x-ray image indicates a place
where the x-ray was absorbed)
Too much exposure can
cause cancer
(lead vest at dentist
protects organs from
unnecessary
exposure)
• Used by engineers
to check for tiny
cracks in
structures.
– The rays pass
through the cracks
and the cracks
appear dark on
film.
GAMMA RAYS
• Shorter wavelength and
higher frequency than Xrays
• Carry the greatest
amount of energy and
penetrate the most.
• The Incredible
Hulk was the
victim of gamma
radiation.
Exploding
nuclear
weapons emit
gamma rays.
Create the Following Chart
Electromagnetic Waves
Facts
Examples
Radio waves (Real)
Radio Waves sends Signals
Radio, TV Reception, MRI, Satellite Dish,
Car Radio, CB Radio, & Radio Tower
Microwaves (Men)
Can be used to send a microwave
communication and to cook
Disk-like antennas on tower and a
Microwave
Infrared (In)
Keep food hot, Communicate with TV, or
anything that produce heat
Lamps, Remote Control, Vegetation
(trees, grass),
Visible Light (Roy-G-Biv)
(Violet)
Anything with colors
Rainbow, pictures, & etc…
Ultraviolet Rays (Underwear Are)
Tan our skin and comes from the Sun
Tanning Salon, UV Rays from the Sun
X-Ray (Extremely)
Used to study bones and treat Cancer
X-Ray and Stars
Gamma Rays (Gorgeous)
Is given off by nuclear explosions that
occur within stars, like our sun & Kills
Sick Cells and Bacteria/Sterilize
Equipments
Stars and Nuclear Explosion
• Electromagnetic Spectrum—name for the range
of electromagnetic waves when placed in order of
increasing frequency
RADIO
WAVES
INFRARED
RAYS
MICROWAVES
ULTRAVIOLET
RAYS
VISIBLE LIGHT
GAMMA
RAYS
X-RAYS
Waves Town Activity
• Brief SUMMARY
• A. All electromagnetic waves travel at the same
speed. (300,000,000 meters/second) in a
vacuum.
• B. They all have different wavelengths and
different frequencies.
– Long wavelength-lowest frequency
– Short wavelength highest frequency
– The higher the frequency the higher the energy.
Falcon Focus
•
•
•
•
•
•
•
•
•
•
•
(8-6.2) Which are mechanical waves?
A. light waves
B. Microwaves
C. Sound waves
D. Radio waves
(8-6.2) A ___ wave can travel in the absence of matter.
A. light
B. sound
C. seismic
D. water
Essential Question
• (8-5) How would you explain how gravity and
friction affects objects?
Create the Following chart
Color of Light
White
Red
Blue
Green
Black
Yellow
Clear
Colors Reflected
Chart Conclusion
st
•1 :
Explain what do you
know about reflection and
absorption of colors of light.
nd
• 2 : Give an conclusion base
on the results of your data or
what you observed.
Falcon Focus
• (8-6.3) In the diagram (pg. 67) in which position
would the fish appear to someone looking at if
from above the surface of the water?
•
• A. A
• B. B
• C. C
• D. D
Essential Question
• (8-6.1) What is a wave and how is a wave
created?