1. WAVES UNIT

2. WAVES UNIT: SWBAT COMPARE WAVES AND LABEL PARTS OF A WAVE
DEFINITION
A disturbance that transfers energy from one place to another
Characteristics
Matter moves in place, energy travels the entire distance
Examples
water waves
Sound waves
Non example
Ball rolling
Waterfall
WAVE
consolo '12, OBJ: swbat label a wave and compare waves

3. definition characteristics Waves that transfer energy through medium
Forces start the disturbance and send it through the medium; the particles of the medium vibrate
Waves that transfer energy through medium
Mechanical wave
Non examples
examples
Seismic wave in an earthquake Sounds of church bells
Ocean waves
Microwave
Light waves
consolo '12, OBJ: swbat label a wave and compare waves

4. consolo '12, OBJ: swbat label a wave and compare waves
The following are various types of mediums. Let’s identify the type of wave would use the medium.
Water:
Rocks and soil:
Air:
When a wave starts-what moves from the beginning to the end of the wave?
energy
Why doesn’t the ocean empty when the waves reach the shore?
Because the waves are transferring energy NOT matter!
Electromagnetic waves like light do not require a medium to transfer energy. They use electric and magnetic fields.
consolo '12, OBJ: swbat label a wave and compare waves

5. consolo '12, OBJ: swbat label a wave and compare waves
Transverse wave
This wave moves perpendicular/at right angles to the force. The force moves up and down causing the wave medium to move in an up and down motion.
Example: ocean waves or light waves
crests
Note the various parts of the wave
wavelength
consolo '12, OBJ: swbat label a wave and compare waves

6. consolo '12, OBJ: swbat label a wave and compare waves
Longitudinal Waves
The motion of the particles and the medium is back and forth
Compressions: where the particles bunch up together.
Rarefaction: places where the particles spread out
consolo '12, OBJ: swbat label a wave and compare waves

7. consolo '12, OBJ: swbat label a wave and compare waves
Review:
TRANSVERSE WAVE
crest
wavelength
amplitude
trough
What type of wave is this? What is the motion of the medium?
Where is the trough? Where is the crest? Where is the amplitude? What is a wavelenght?
consolo '12, OBJ: swbat label a wave and compare waves

8. consolo '12, OBJ: swbat label a wave and compare waves
How are frequency and wave length related 1.2
Frequency:
Number of wave lengths that pass a certain point
Wavelength:
Distance from one crest, or trough to the next
When the frequency increases, the wavelength decreases.
Remember from the review where wave length is.
This is a wave pendulum designed using billiard balls, this device shows how 15 individual pendulum of different (but relative) lengths that have been adjusted to have successively increasing periods. When all the balls are released at the same time, the different periods cause the pendulums to cycle through all possible relative phase relationships, eventually returning to the beginning arrangement. When it cycles through it's phases, different wave patterns are noticed! Visit our website at
consolo '12, OBJ: swbat label a wave and compare waves

9. consolo '12, OBJ: swbat label a wave and compare waves
Reflection
Refraction
Diffraction
Interference
Spreading out of waves through opening or past obstacle
The bouncing back of a wave after it strikes a barrier
Bending of a wave as it enters a medium other than 90 deg
The meeting and combining of waves
consolo '12, OBJ: swbat label a wave and compare waves

10. consolo '12, OBJ: swbat label a wave and compare waves
Interference of waves
Constructive interference is the building up of waves when two waves align exactly, and thus the amplitudes are added together resulting in a bigger wave.
So if two waves met and the first had an amplitude of 2 and the second an amplitude of 2 then at the crest where they met the new waves amplitude would be 4. after merging they then return to their original directions and amplitudes.
consolo '12, OBJ: swbat label a wave and compare waves