A wave is a disturbance that transfers energy through a medium or space. There are two main types of waves: mechanical waves, which require a medium such as air, water or solid material to travel; and electromagnetic waves, which can travel through empty space. Mechanical waves can be transverse, with the disturbance moving perpendicular to the direction of energy transfer, or longitudinal, with the disturbance moving parallel. Examples of transverse mechanical waves include water waves and seismic S-waves, while longitudinal mechanical waves include sound waves and seismic P-waves. Electromagnetic waves include visible light, radio waves, microwaves and more.

1. WAVES

2. Waves & Disturbance
Waves can be anything that transport Energy

3. WAVE
• Wave is a disturbance “change” that
transfers energy from one place to
another without transferring matter.
• https://phet.colorado.edu/sims/html/w
ave-on-a-string/latest/wave-on-a-
string_en.html

4. Energy transferred by a wave lifts the duck.
Causing to move it up & down.
But the duck remains at the same place.

5. Sources of wave?

6. Mechanical Wave
• A wave that can travel through matter (solid, liquids, and gases)
Mechanical
wave
Transverse
wave
Up & down
perpendicular
Longitudinal
wave
Back & forth
parallel

7. SLIDE 7: Mechanical Wave+
• Is a wave that can travel through matter (solids, liquids, and gases)
• What is the medium in this example? LMS question

8. What is the medium?+
• A material in which a wave travels is called a medium
• What is the medium of sound wave?
• What is the medium in this example? AIR “gases”

9. Electromagnetic Waves
• EM waves are waves that can travel
through empty space. They do not
require a medium.
• EM waves are transverse waves.
• The EM spectrum consists of waves
including gamma rays, x-rays, UV light,
visible light, IR waves, microwaves and
radio waves.
• EM waves travel through space at the
speed of light.
• Mechanical waves are waves that must
travel through some form of matter to
carry their energy.
• The matter that carries a wave is called
the medium and includes matter such
as air, water, rock, metal, etc.
• Mechanical waves can be either
transverse or longitudinal waves.
• In a given medium, the speed of waves
is constant. Waves travel very quickly
through solids, less quickly through
liquids and slowest through gases.
Mechanical Waves
A wave is a disturbance that carries energy through matter (a medium) or space:

10. Transverse wave & Longitudinal wave

11. Transverse Wave
• Is a wave in which the disturbance is perpendicular to the direction
the wave travels

13. LONGITUDINAL WAVE+
makes the particles in the medium move parallel to the
direction that the wave travels
Moves Back & Forth
Example of Longitudinal wave:

14. LONGITUDINAL WAVE
Compression & Rarefactions
• Compression: the region where the particles are closest together.
• Rarefactions: the region where the particles are far

15. Transverse Waves
• Transverse waves can be modeled by
using a sine wave.
• Types of transverse waves include EM
waves and ocean waves.
• Depending on the type of wave,
transverse waves may or may not
require a medium.
• Longitudinal waves can be modeled by
using a spring.
• Sound waves are longitudinal waves.
• Longitudinal waves are mechanical
waves – they require a medium.
Longitudinal Waves
compression
rarefaction

16. Types of waves
WAVE
MECHANICAL
Transversal
longitudinal Sound
Electromagnetic
light
Radio,
microwave

17. Waves

18. transverse wave
Mechanical Waves
Ex: sound
earthquake
s-waves
transverse wave
require a medium
do not require a medium
earthquake
p-waves
Electromagnetic Waves
longitudinal wave
transverse wave
Waves
Ex: light

19. Waves
Electromagnetic Waves Mechanical Waves
do not require a medium require a medium
Waves
transverse wave longitudinal wave
earthquake
s-waves
earthquake
p-waves
Ex: light
Ex: sound
transverse wave

20. Electromagnetic wave
Electromagnetic wave can travel through empty space

21. PRACTICE
• https://www.liveworksheets.com/rt1226546ep

22. Questions. Page: 134
• 2) What difference between transverse & longitudinal wave:
• Transverse wave moves (up & down/ perpendicular to the motion)
• Longitudinal wave (back &forth/ parallel to the motion)
• 3) what cause a wave?
A) crest B) rarefaction C) rope D) vibration (disturbance)
• 4) how are sound waves & water waves similar? And different?
• Sound wave is longitudinal wave/ medium is Air (gas)
• Water wave is transverse & longitudinal/ medium is water

23. Question
• 6) mechanical wave & electromagnetic wave