Post on 04-Jan-2016
Bell Work
• List 5 different kinds of waves you have seen in your lifetime.
What are Waves?
Objectives:• How do matter and
energy interact when waves are generated?
• What are the three main types of waves?
What is a WAVE?• A disturbance that transfers energy from
place to place.
• Waves carry energy!
• After the wave has moved, the disturbance is gone. Everything is calm again.
How does a wave travel?• A wave must have something to
travel through. MATTER!
• The material through which a wave travels through is called a medium.
What are some examples of mediums that waves can
travel through?
Mechanical Waves
• Waves that require a medium through which to travel through are called mechanical waves.
• Waves do not carry the medium as they move through it.
• Waves just carry energy.
• The duck does not move sideways toward to shore.
• The duck moves up and down and the WAVE moves toward to shore.
Electromagnetic Waves
• Not all waves require a medium in order to travel.
• Light from the sun can travel through empty space. Empty space is not a medium
What CAUSES waves?• Waves are generated when a source
of energy forces the matter in a medium to vibrate.
• Vibration is a repeated back-and-forth or up-and-down motion.
• Motion is the source of the wave.
The transfer of energy:
• A moving object has energy.
• The moving object can transfer energy to a nearby medium, creating a wave.
transfer
Wave Motion
Energy
Mechanical waves
Electromagnetic waves
A medium to pass through
include
requiredon’t require
Waves
include
Classification• Waves are classified according to how they travel
through a medium.
• Three types of waves:
1. Transverse waves
2. Longitudinal waves
3. Surface waves
Transverse Wave
• Waves that move the medium at right angels to the direction in which the waves are traveling.
• Across
• Highest part of the wave is called the crest.
• The lowest part of the wave is called a trough.
Transverse Wave
Can you think of any transverse waves?
Longitudinal Wave
• Moves the particles of the medium parallel to the direction that the waves are traveling.
• Coils of a spring• Compressions – parts where the coils are close
together• Rarefactions – parts where the coils are spread out
Longitudinal Wave
Can you think of any longitudinal waves?
Surface Wave
• Combinations of transverse and longitudinal waves.
• The waves occur at the surface between two media, such as water and air.
• Up and down and back and forth
Objectives Review:• How do matter and energy interact
when waves are generated?
• What are the three main types of waves?
Assignment: