1. 1
WAVES

2. Recognize that all waves transfer energy.2
Recognize that all waves
transfer energy.
Explain the phenomena of reflection, refraction, interference, & diffraction.
Relate frequency & wavelength to the energy of different types of electromagnetic waves & mechanical waves.
Relate the speed of sound to different mediums.
Explain the Doppler Effect in terms of everyday interactions.
Compare and contrast the characteristics of electromagnetic and mechanical (sound)
waves.

3. 3
Waves
Waves are disturbances that carry energy through matter or space. Clip
Waves can be visible or invisible evidence of energy transfer.
The material does not actually travel with the wave….. only the energy is carried.

4. Types of Waves Two types of waves:4
Two types of waves:
Mechanical
Non-Mechanical
Mechanical: waves need a medium in order to travel.
Examples: Sound, water
Non-mechanical: waves do not need a medium to travel.
Examples: light, gamma waves, microwaves, x-rays

5. Mechanical Waves A medium is the material a wave travels through5
Mechanical Waves
Waves that require a medium to travel.
A medium is the material a wave travels through
Sound and water.
Light waves are NOT Mechanical Waves.

6. Transverse waves Water, light Longitudinal waves sound6
Ways that waves travel
Transverse waves
Water, light
Longitudinal waves
sound

7. Transverse Waves Transverse waves are UP & DOWN movements.7
Transverse Waves
Transverse waves are UP & DOWN movements.
The displacement of individual particles is perpendicular (at right angles) to the direction of the wave.
EX: water waves, radio waves (all EM waves)

8. Describing a Transverse Wave8
Describing a Transverse Wave

9. The higher the amplitude, the more energy the wave is carrying 9
amplitude
The higher the amplitude, the more energy the wave is carrying
In a longitudinal wave- it’s how tight the compressions are

10. Frequency & Wavelength10
Wavelength
Distance between to identical points on adjacent waves.
Meters
As the wavelength decreases the frequency increases λ
Frequency
Number of waves per second
Hertz

11. Movement of a Transverse Wave11 9
Movement of a Transverse Wave
CLIP

12. Remember: Energy is transferred ----NOT THE MATTER!--12
Example - Water
Remember: Energy is transferred ----NOT THE MATTER!--

13. Longitudinal Waves 13
Longitudinal waves are a series of PUSHES & PULLS in which the motion of the medium is in the same direction as the wave
Ex. Sound Waves

14. Characteristics of a Longitudinal (Compressional) Wave14
Characteristics of a Longitudinal (Compressional) Wave

15. Parts of a Longitudinal wave15
Parts of a Longitudinal wave
Compressions & Rarefactions
Rarefaction is a place where the atmospheric pressure is lowest.

16. Speed of a wave ν = f λ ν is the velocity (m/s)16
Speed of a wave
ν = f λ
ν is the velocity (m/s)
f is the frequency (hertz)
λ is the wavelength (m)
The speed of a mechanical waves is constant for any given medium..
The speed of a wave changes as it moves through different media

17. Wave interactions with matter17
Wave interactions with matter
Reflection occurs when a wave hits another wave or object that it cannot pass through and bounces back.

18. 18

19. 19
Diffraction occurs when a wave passes through an opening and spreads out
Diffraction is a wave phenomenon that is dependent on wavelength
Light waves bend as they pass by the edge of a narrow aperture or slit 

20. 20
Constructive Interference occurs when two or more waves hit the same point and combine to produce a larger single wave.
Destructive Interference occurs when two or more waves hit the same point and combine to produce a smaller single wave.

21. Constructive Interference

22. Constructive Interference
Clip
Constructive Interference
Destructive Interference