1.	What are Waves?
a.	Mechanical waves are produced when a source of energy causes a medium to vibrate.
b.	Mechanical waves are classified by how they move.  There are two types of mechanical waves:  transverse waves and longitudinal waves.
c.	Key Terms
i.	Wave
ii.	Energy
iii.	Medium
iv.	Mechanical wave
v.	Vibration
vi.	Transverse wave
vii.	Crest 
viii.	Trough
ix.	Longitudinal wave
x.	Compression
xi.	Rarefaction
2.	Properties of Waves
a.	The basic properties of waves are amplitude, wavelength, frequency, and speed.
b.	The speed, wavelength, and frequency of a wave are related to one another by a mathematical formula:  Speed = Wavelength x Frequency
c.	Key Terms
i.	Amplitude
ii.	Wavelength
iii.	Frequency
iv.	Hertz (Hz)
3.	Interactions of Waves
a.	When an object or a wave hits a surface through which it cannot pass, it bounces back.
b.	When a wave enters a new medium at an angle, one side of the wave changes speed before the other side, causing the wave to bend.
c.	When a wave moves around a barrier or through an opening in a barrier, it bends and spreads out.
d.	There are two types of interference:  constructive and destructive.
e.	If the incoming wave and a reflected wave have just the right frequency, they produce a combined wave that appears to be standing still.
f.	Key Terms
i.	Reflection
ii.	Law of reflection
iii.	Refraction
iv.	Diffraction
v.	Interference
vi.	Constructive interference
vii.	Destructive interference
viii.	Standing wave
ix.	Node
x.	Antinode
xi.	Resonance
4.	Seismic Waves
a.	Seismic waves include P waves, S waves, and surface waves.
b.	A seismograph records the ground movements caused by seismic waves as they move through Earth.
c.	Key Terms
i.	Seismic wave
ii.	P wave
iii.	S wave
iv.	Surface wave
v.	Tsunami
vi.	Seismograph