Post on 13-Jan-2016
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Mr. Z’s “Introduction to Waves” Unit
Mr. Z about to catch some “Air”
Mr. Z’s “Riding One Home!”
Mrs. Z
AIM: What is a Wave?
Identify what causes waves.
Identify what waves need.
Identify “how” a wave moves.
AIM: What is a Wave?
Wave, Medium, Particle
AIM: What is a Wave?
Physics is the study of matter and ????
AIM: What is a Wave?
DEMO: How Do Waves Travel?
•Let’s float a cork in a pan of water.•Now let’s produce some waves in the pan by gentle tapping.
Draw a diagram of what you and describe the movement of the wave relative to the movement of the cork!
AIM: What is a Wave?
DEMO: How Do Waves Travel?
•The cork bobs up and down;
•The waves moves rather rapidly to the sides of the container.
•They don’t appear to move the same way, do they?
Compare and contrast the movement of the wave to the motion of the duck in the figure.
What is the difference?
Infer what the duck's motion would be like if the wave moved twice as fast.
AIM: What is a Wave?
DEMO: Examine the waves formed in water using the O/H and a clear pan
DEFINITION:
•a wave is a disturbance that transfers energy (not matter) from place to place.
•Typically the disturbance MAY be temporary. •After the wave passes, there is "calm”.
DEMO
Let’s tie a red ribbon to rope and demonstrate a wave
Which way did the wave move?
Did the ribbon move the same way?
Which way did the ribbon move?
Why did the ribbon not move in the same direction as the wave?
What is needed for a wave?
What do water waves travel through? Water
AIR
ROPE
What does “water”, “air” and “rope” all have in common here?
What does sound waves travel through? What do Rope waves travel through ….
They allow the wave to pass through it!
Most waves need a medium in which to travel.
Water, Air, Rope are all mediums for different kinds of waves.
DEFINITION:
Most waves needs a medium in which to travel.
Definition: The “medium” is defined as the substance through
which a wave can travel
Waves that require a medium are called mechanical waves
Although waves travel through a medium, they do not carry the
medium itself!
Example: The rope did not move, only the energy through it moved!
The rope moved up and down, it did not move with (in the direction) of the
wave
Waves that require a medium are called mechanical waves
Although waves travel through a medium, they do not carry the
medium itself!
The wave is energy.
The medium is made of matter.
After the wave passes, the matter is still in the same place!
Not all waves require a medium, but most do.
Light waves do not require a medium
What causes waves?
Waves are initially caused by a movement or transfer of energy, called a vibration.
Some examples of vibrations could be water droplets, striking a tuning fork, your vocal cords, wind forming ocean
waves
.
THINK ABOUT IT:
What do all moving objects have? Energy
What happens when a moving object comes in contact with another object? part of its energy is
transported to the other object
If that “other object” is a suitable medium what do you think will happen?
http://www.explorescience.com/activities/Activity_page.cfm?ActivityID=50
Class Activity:
W/S Concepts 7-1
AIM: What is a Wave?
Homework:
INTERNET QUESTIONS
AIM: What is a Wave?