TAKS Objective 4
The student will demonstrate an
understanding of motion, forces, and
energy.
TEKS 8.7 Science Concepts
The student knows that there is a
relationship between force and motion.
The student is expected to:
B. recognize that waves are generated
and can travel through different media.
Lesson Objectives
•
•
•
The learner will be able to differentiate
between the motion of the wave and the
motion of the matter carrying the wave.
The learner will identify waves that
require a medium to move through and
waves that travel through empty space.
The learner will demonstrate that waves
carry energy.
Lesson Objectives
• Students will generate waves that pass
through different media.
• The student will demonstrate that a wave
moves forward while the material through
which it passes is displace only slightly
and momentarily.
• Students will measure wave properties.
Background
• What is a wave?
– A disturbance in which energy is transferred
without causing any permanent displacement
of the medium (e.g., air, water, earth, empty
space).
How do Waves Move?
• Longitudinal- (e.g., Compression waves)
– Energy moves parallel to medium
– Sound waves, dominos, some earthquake
• Transverse- (e.g., S waves)
– energy moves perpendicular (right angles) to
medium
– Electromagnetic, some earthquake
Major Wave Types
•
Electromagnetic- produced by the
vibration of electrons within atoms on the
Sun's surface.
– Does not require particles to transfer energy
– Usually transverse (S) waves
• Mechanical- must have a medium to
transfer energy
– Need particles to interact to transfer energy
– Compression (sound), surface (water), both
compression & transverse (earthquakes)
http://www.glendaleh.schools.nsw.edu.au/faculty_pages/ind_arts_web/bridgeweb/com
mentary.htm
Sound Waves
Ocean Waves
Earthquake (Seismic) Waves
How Are Waves Made?
• All waves are made by vibrations
– Sound- vibrate matter
• need molecules to vibrate so, no sounds in space
– Ocean waves are produced by wind and the
gravitational pull of moon produces ocean
tides.
http://www.physicalgeography.net/fundamentals/8r.html
– Electromagnetic waves- electric field and
magnetic fields combine
• DON’T need molecules - travels through empty
space
Electromagnetic Waves
• Radio, radar, microwaves, infrared, visible
light, ultraviolet, xray, gamma
Redheaded Martians Invade
Venus Using Xrays & Gamma rays
Where do Electromagnetic
waves come from?
Radio - sound and video of television is carried by
shorter radio waves (wavelengths < 1 meter),
and are modulated for broadcast much like FM
radio. Radio waves are also produced by stars
in distant galaxies.
Microwaves - Microwaves & radar are high
frequency radio waves and are emitted by the
Earth, buildings, cars, planes, and other large
objects. In addition, low-level microwave
radiation permeates space, where it is
speculated to have been released by the "Big
Bang" during creation of the universe.
Infrared - Almost all objects emit infrared rays,
depending on the temperature of the object.
Visible light - White light originates from a
variety of natural and artificial sources,
including the sun, chemical reactions (fire),
incandescent tungsten filaments, and
fluorescent lamps (ROYGBIV)
UV - The sun is a constant source of ultraviolet
radiation. Stars and other hot celestial objects
in outer space emit ultraviolet radiation.
X-rays - Medical tools and hot gases in
outer space emit X-rays
gamma - radioactive materials (natural
and artificial) but also originate from
nuclear explosions and a variety of
sources in outer space. They also
originate from the hottest regions of
the universe including supernova
explosions, neutron stars, pulsars, and
black holes.
Misconceptions
True or False?
When a wave moves, the
medium flows with the wave
Answer:
Answer: False
The medium moves very
little - waves just transfer
energy, not matter
True orTrue
False
or False?
Radio waves are
Radio waves are sound
sound
waves
waves
Answer: False
Equipment in the radio converts
electromagnetic energy into
sound waves
(XM radio is FM radio
broadcast from satellites)
True or False
There is sound in the
vacuum of space
Answer: False
Sound requires matter
to vibrate
Chapter Activities
A variety of experiences with waves are
designed to introduce students to waves.
Students will generate and study waves
traveling through many different types of
medium.
Engage
• Cheerleader
• Poof- demo
Explore
Complete the falling like
dominos learning
experience.
Explain
1. Was energy transferred?
2. Did we significantly change the position of
the dominos?
Elaborate
• I Can Hear You (telephone)
• Making Waves
• You Light Up My Life
Evaluate
Create an illustrated poem (cinquain, haiku,
limerick) for each type of wave.