1. WAVES CARRY ENERGY! MECHANICAL WAVES
Waves are rhythmic disturbances that carry ENERGY without carrying
matter. Molecules transport the energy in a wave by colliding with the
molecules around them. Mechanical waves travel through matter by
creating vibrations in a medium – solid, liquid or gas. Examples: Sound,
water or seismic waves.
MECHANICAL WAVES
Use matter to transfer ENERGY from particle to particle
Matter = Medium
(requires it)
TRANSVERSE
COMPRESSIONAL
(Longitudinal)

2. WAVE PROPERTIES WAVELENGTH CREST AMPLITUDE TROUGH FREQUENCY
POSITION
TROUGH
FREQUENCY
CREST – highest point of a wave
TROUGH – lowest point of a wave
WAVELENGTH – distance from peak to peak
AMPLITUDE – the distance a wave rises/falls from its rest position
FREQUENCY – the number of waves passing a given point

3. Frequency and Wavelength
Longer wavelengths Larger frequencies
result in smaller result in shorter
frequencies. wavelengths.
As the frequency of a wave increases,
its wavelength decreases.
Frequency and wavelength are related!

4. TRANSVERSE WAVES EXAMPLES:
oscillating, repetitive motion in which the medium moves at right angles
to the wave direction
particles of the medium moving perpendicular (moves at right angle)
WAVELENGTH
CREST
AMPLITUDE
TROUGH
EXAMPLES:
Slinky, secondary seismic wave, ocean waves,
light waves, guitar strings, and a stadium wave

5. ] ] ] COMPRESSIONAL WAVES
particles of the medium moving parallel to the direction of the wave
oscillating, repetitive motion that moves in the same direction as the medium
matter in the medium moves forward or backward in the same direction
of the wave
Transfers energy from molecule to molecule through solids, liquids & gases
Needs a medium to travel – space is a vacuum without air – sound does not
travel in space ]
RAREFACTION ] ]
COMPRESSION
WAVELENGTH
EXAMPLES -
Sound, dominoes, primary seismic waves, bats hearing, sonar

6. Electromagnetic waves are not caused by a disturbance of particles in a medium. Instead, it is produced by an interaction between an electric and a magnetic field.
Field - force or push in a region
Speed of light – 300,000 kmps
Medium - matter
Electromagnetic waves travel in
a vacuum at the same speed

7. ELECTROMAGNETIC SPECTRUM
Visible Light
0.000,000,000,000,000,1
0.000,000,000,000,01
0.000,000,000,001
0.000,000,000,1
0.000,000,01
0.000,001
0.000,1
0.01 1
100
10,000
1,000,000
100,000,000
Gamma Rays
Radio waves
X-rays
Microwave
Cosmic rays
Ultraviolet
Infrared
HIGH
LOW
Frequency
Short
Long
Wavelength
(192)

8. ELECTROMAGNETIC WAVES
Are transverse waves that do not require matter to carry energy.
They are produced by the motion of electrically charged particles.
They can travel through solid, liquids or gas faster than mechanical
waves.
They can also travel through space, or through a vacuum where
no matter exist.

9. LIGHT
Light is a electromagnetic wave that travels through air at about 300,000 km/s.
Bright lights have greater amplitudes (more energy) than the waves that make up dim light.
Because frequency and wavelength are related, either the wavelength or frequency of a light wave determines the color of the light. Blue light has a larger frequency and shorter wavelength than red light. Red light has a shorter frequency and a longer wavelength.
Light travels faster through gases than in solids or liquids.
Example: speed of light is one and a half times faster in air than it is in glass.

11. LIGHT WAVE BEHAVIOR Reflected Absorbed Transmitted
Light rays that come in contact
with a object that reflects it will
bounce right back at the same
angle it came in at - like your
reflection In a mirror.
Reflected
Absorbed
Transmitted
Light rays that come in contact
with a dark object will be
absorbed into it, making the
object warmer - like your dark
colored shirt or car.
Light rays that come in contact
with something that is
translucent, or clear, will
“transmit” or go through the
object - like a window or a glass.

12. A MIRAGE IS AN ILLUSION CAUSED BY THE
REFRACTION OF LIGHT WAVES, MAKING
OBJECTS THAT ARE FAR AWAY TO BE
NEARBY, FLOATING IN THE AIR OR
UPSIDE DOWN.

13. Light rays refract as they enter and leave each rain drop
Light rays refract as they enter and leave each rain drop. Each color refracts at different angles because of their different wavelengths, so they separate into the colors of the spectrum.

14. As sunlight passes through the atmosphere, its wavelength is scattered by particles of dust in the air. Red and yellow wavelengths pass through the air directly, while blue light is scattered. It is this scattered blue light (short wavelength) that reaches our eyes
when we see blue sky.

15. REFRACTION Examples: Eyeglasses Binoculars Telescopes Microscopes
Refraction is the bending of a wave as it moves
from one medium into another.
Air (less dense)
Water (dense)
Normal
Examples:
Eyeglasses
Binoculars
Telescopes
Microscopes
ANGLE OF INCIDENCE
Refracts
Angle of
refraction

16. Incident Ray
Normal
Reflective Ray
Reflection occurs when a wave strikes an object and bounces off.

17. INTERFERENCE Destructive – a wave with a smaller amplitude is formed.
The ability of 2 waves to combine
and form a new wave when they overlap.
Constructive = combines to
make a new wave, increasing
its amplitude.
INTERFERENCE
Pg. 202

19. R O Y G B I V

20. The diffraction grating has thousands of tiny parallel lines etched into it.
Diffraction is the bending of waves around barriers or through openings.
What colors do you see through the diffraction grating?
What are some examples of patterns you can observe?
Where did all the beautiful colors come from?
Have you ever used a prism to separate white light into its many colors?
If so, what did you observe?

21. SOUND
Sound is a mechanical wave that travels through air at about 340 m/s or 1100 ft. per second.
Loud sound waves are greater amplitudes than soft sound waves.
Loud sounds carry more energy than soft sounds.
Sound travels faster in a solid than a liquid, and faster in a liquid than a gas.
In a sound wave, either the wavelength or frequency determines the pitch.
Pitch is the high or low of a sound.
Sound level (loudness) is measured in units called decibels.
Vocal cords produce sound by vibration.
As the frequency of a sound wave increases, its wavelength decreases.

22. DIFFRACTION Diffraction is the bending of waves around a barrier.
Example: Music going into another room.
Light shining into the next room.
Light waves do not diffract as much as sound
waves do.
DIFFRACTION
1.What colors do you see through the diffraction grating?
2. What are some examples of patterns you can observe?
3. Where did all the beautiful colors come from?
4. Have you ever used a prism to separate white light into its many colors?

23. Sound – Pitch and Loudness
Pitch - depends on frequency
High frequency – high pitch
Low frequency – low pitch
Loudness – depends on energy of amplitude
Intensity of the wave – amount of energy in a certain amount of time
The greater the amplitude, the louder the sound

24. ] ] ] COMPRESSIONAL WAVES
particles of the medium moving parallel to the direction of the wave
oscillating, repetitive motion that moves in the same direction as the medium
matter in the medium moves forward or backward in the same direction
of the wave
Transfers energy from molecule to molecule through solids, liquids & gases
Needs a medium to travel – space is a vacuum without air – sound does not
travel in space ]
RAREFACTION ] ]
COMPRESSION
WAVELENGTH
EXAMPLES -
Sound, dominoes, primary seismic waves, bats hearing, sonar