Transcript 4/20 & 4/21 - 7th Grade Agenda

10/11 & 10/12 - 7th Grade Agenda
Learning Objective: Learn the difference
between transparent, translucent and opaque
materials.
Collect: Reading & Note Taking : p. 35- 36
Collect: Parent Signature on Grade Print out
Transparent, Translucent and Opaque
Video: Science in Action Waves (Start in the
middle)
Class Reading: p. 44 - 50
HW: Reading & Notetaking : p.37 - 40
Daily Reflection
• Prompt: Give 5 examples of
electromagnetic waves. What is the one
difference between all the electromagnetic
waves? .
Electromagnetic Wave
• An electromagnetic wave
consists of vibrating electric and
magnetic field that move through
space at the speed of lig____
ht
What are some examples of
electromagnetic waves?
•
•
•
•
•
•
•
Radio Waves
TV Signals
Microwaves
Infrared rays
Light
Ultraviolet rays
X-Ray
How fast do electromagnetic
waves travel?
•
•
•
•
It is the fastest thing in the universe
300,000 km per second
186,000 miles per second
It takes 8 minutes for light to travel from the sun
to the earth
• It takes 3 million years for light to travel from the
nearest galaxy (andromeda) to the earth
Electromagnetic Wavelength
How do we use Radio Waves &
Microwaves?
• Radio & TV
signals
• Microwave Oven
• Radar
• MRI
• Cell phone
Using Microwaves
• Why do you see sparks you put metal objects in
a microwave?
• Because of the build up of electrical energy in
the metal
• The long wave length of Microwaves can pass
right through glass and plastic. That is why
microwaves do not heat glass and plastic
containers.
Cell phone towers
• These towers are placed 1 -2
miles apart in a city
icro
• They use M______wave
to
communicate with cell
phones
• They can be used to locate
ation of the caller.
the loc_______
How do we use Infrared Rays?
• Conventional Oven
• Heat Lamps
• Thermograms
Transparent Materials
• Transparent
material
mit most
trans_____
of the light that
strike it.
Translucent Materials
• A translucent
material sca____
tters
light as it passes
through, just as
smoke, fog, and
clouds scatter light
as it passes
through the air.
Opaque Materials
• An opaque
material refl_____
ects
or absorbs all of
the light that strikes
it.