1. WAVES

2. WAVES a disturbance that transfers energy
Carries energy from one place to another
Classified by what they move through
Mechanical Waves the energy is transferred by vibrations of medium (medium = matter) ex/ ocean waves move through water
Electromagnetic waves (EM Waves) the energy moves through disturbances in the electromagnetic field.
Physics The act or process of propagating, especially the process by which a disturbance, such as the motion of electromagnetic or sound waves, is transmitted through a medium such as air or water.
A medium is a substance or material which carries the wave

3. WAVE STRUCTURE CREST (peak) AMPLITUDE resting to max peak WAVELENGTH
TROUGH

4. MECHANICAL WAVES
require a medium (the material through which the disturbance is moving) to transmit energy
travel through & gradually lose energy to that medium
Examples:
water, sound, rope, & spring waves
Mechanical Media:
water, air, rope, spring
Making a pulse

5. MECHANICAL WAVES Classified by how medium vibrates
           
           
Classified by how medium vibrates
Pulse = direction of energy transfer
Vibration = direction of vibration of medium relative to pulse
3 types:
Longitudinal,
transverse,
surface

6. MECHANICAL WAVES Classified by how medium vibrates Longitudinal Waves:
Vibration is in the same direction as wave pulse (parallel to wave pulse)
Transverse Waves:
Vibration is at 900 (right angles) to wave pulse
Surface Waves:
Vibration is circular
Ex/ Ocean waves; surface waves

7. TRANVERSE WAVES Sideways or up & down Examples:
           
Vibration is perpendicular to the direction of the motion of the wave
Sideways or up & down
Examples:
S-type earthquake waves
Electromagnetic (EM) or light waves

8. LONGITUDINAL WAVES
Vibration is parallel to the direction of the motion of the wave
Back and forth (compression & rarefraction)
Also called compression or pressure wave
Examples:
P-type earthquake waves
Sound waves
Rarefraction (expansion)
Compression

9. Waves describe the Earth
P waves move through solids & liquids
P waves move through solids & liquids
S waves move through solids only!!!
Are these MECHANICAL WAVES????
YES!! Seismic waves need a medium (the earth!)

10. CHARACTERISTICS OF WAVES
Waves are described according to their
Amplitude measures DISPLACEMENT size of the disturbance
Wavelength  distance of a “repeating unit” Also called a cycle
Velocity v speed = how fast wave travels

11. AMPLITUDE Distance between “rest & crest” or “rest & trough”
Gives indication of “power” or “strength” of wave (magnitude of earthquake = Richter scale)
Does not affect velocity of wave
Determines loudness (sound) or brightness (EM wave)

12. WAVELENGTH 
Distance between any two repeating points on a wave crest-crest, trough-trough, expansion-expansion, compression-compression
Determines what colors we see; what notes we hear (pitch)
Shorter wavelengths have more cycles per minute because they aren’t as long

13. VELOCITY v the rate at which the energy travels; speed & direction
Depends on medium
Mechanical waves travel faster through dense mediums
EM Waves are faster through less dense mediums

14. Frequency ƒ
How often number of wavelengths that pass any point per second
measured in wavelengths/second or cycles/second Hertz (Hz) = number of wavelengths in 1 second
Frequency is related to velocity: v = ƒ 

15. PERIOD T
How long Amount of time for one wavelength to pass a point
Related inversely to frequency
Period = 1
Frequency
When an event occurs repeatedly, then we say that the event is periodic and refer to the time for the event to repeat itself as the period.
1 = T f