Contributed by:
Waves, Types of waves, Mechanical waves, Transverse waves, Compressional waves, EM waves
1.
Essential Question:
What are the characteristics
of mechanical and
electromagnetic waves?
(S8P4a,d,f)
2.
What are Waves?
Rhythmic disturbances that carry
energy without carrying matter
3.
• Mechanical Waves – need matter (or medium)
to transfer energy
• A medium is the substance through
which a wave can travel. Ex. Air;
water; particles; strings; solids;
liquids; gases
• Electromagnetic Waves – DO NOT NEED
matter (or medium) to transfer energy
• They do not need a medium, but
they can go through matter
(medium), such as air, water, and
4.
Mechanical Waves
Waves that need matter
(medium) to transfer energy:
Examples: Sound waves,
ocean waves, ripples in
water, earthquakes, wave of
people at a sporting event
6.
Answer the following question with an
elbow partner:
Look back at the examples of mechanical
waves. If waves transfer energy, which
type of mechanical wave do you think
transferred the most energy? Why?
7.
(Mechanical) Waves
Waves in which the particles vibrate in an
up-and-down motion.
The direction in which the wave travels is
perpendicular to the direction of the
disturbance
**Remember: t=90 degrees
waves in water
Seismic waves
8.
Parts of a
Transverse Wave
The crest is the
highest point on
a wave.
9.
Parts of a Transverse
Wave
The trough is the
valley between
two waves, is the
lowest point.
10.
Parts of a Transverse Wave
The wavelength is the horizontal
distance, either between the crests or
troughs of two consecutive waves.
11.
Parts of a Transverse Wave
The amplitude is the peak (greatest) value (either positive or
negative) of a wave. The distance from the undisturbed level to the
trough or crest.
12.
An ocean wave is an example of
a mechanical transverse wave
14.
Compressional Wave (longitudinal)
A mechanical wave in which matter in the
medium moves forward and backward along
the same direction that the wave travels.
Ex. Sound waves A slinky is a good illustration
of how a compressional
wave moves
15.
Parts of a Compressional Wave
The compression is the part of the
compressional wave where the particles are
crowded together.
16.
Parts of a Compressional
Wave (Longitudinal)
The rarefaction is the part of the
compressional wave where the particles
are spread apart.
17.
Parts of a Compressional Wave
The wavelength is the distance from
compression to compression or rarefaction to
rarefaction in a compressional wave.
20.
Electromagnetic Waves
• Waves that that can travel through space and
matter
• **DO NOT NEED matter
(medium) to transfer energy
• Electromagnetic waves are
considered transverse waves
because they have similar
characteristics; therefore, they have
the same parts.
21.
EM Waves
Consists of changing electric and magnetic
fields.
22.
EM Waves
Examples: All EM waves give off
radiation
:TV & radio waves,
X-rays, microwaves, lasers, energy from
the sun, visible light, infrared, UV rays,
Gamma rays
Travel at the speed of light
186,000 miles per second or 300,000,000
meters per second
23.
The electromagnetic spectrum illustrates the
range of wavelengths and frequencies of
electromagnetic waves.
24.
1. Which of the following has the longest wavelength? Microwave Gamma Ray Radio Wave Ultraviolet Light
2. Which of the following has the highest frequency? Microwave Gamma Ray Radio Wave Ultraviolet Light
3. Compare the wavelength and frequency of a radio wave to the wavelength and frequency of a gamma ray.
4. Compare the wavelength of infrared light to the wavelength of ultraviolet light.
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