39 terms

# Waves

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mechanical waves
need a medium on which to travel
transverse waves
particles of the medium vibrate perpendicular to the motion of the wave
longitudinal waves
particles of the medium move parallel to the direction of the wave
water wave
combination of transverse and longitudinal
electromagnetic wave
doesn't need a medium, travel at the speed of light in a vacuum
matter wave
solid which has wave properties
wave pulse
a single bump or disturbance
periodic wave/traveling wave
wave which continues to move
amplitude
distance from the equilibrium position
crest
top of the wave
trough
bottom of the wave
wavelength
distance during which motion repeats itself
period
time it takes for one complete vibration
frequency
number of cycles per second
incident wave
incoming wave that strikes the boundary
reflected wave
returning wave
inverted wave
upside down
reflected wave is upright
if a wave travels from a more dense to a less dense medium..
reflected wave is inverted
if a wave travels from a less dense to a more dense medium..
law of reflection
angle of incidence is equal to the angle of reflection
refraction
changing direction of the wave at the boundary between two different mediums
diffraction
bending of waves around a barrier
total internal reflection
only occurs when wave going from a more dense to a less dense medium
critical angle
refracted ray lies right along boundary between mediums. Angle of refraction = 90 degrees
total internal reflection
any incidence angle above the critical angle
echos
reflected sound waves
frequency
pitch
beats
difference in pitch
Principle of Super Position
algebraic sum of the displacements caused by individual waves
interference
result of superposition
constructive interference
resulting wave has a larger amplitude
destructive interference
resulting wave has a smaller amplitude
standing waves
a pattern which results from the interference of two or more waves traveling the same medium. always characterized by an alternating pattern of nodes and antinodes
nodes
result of the meeting of a crest with a trough. leads to points of zero amplitude
anti-nodes
positions along the medium where there are points of maximum amplitude due to a crest meeting a crest or a trough meeting a trough
normal
imaginary line perpendicular to the boundary
Snell's Law
mathematical equation which relates the indices of refraction and angles for a light ray traveling from one medium to another
incident ray
incoming light ray
refracted ray is bent away from the normal
if light travels form a more optically dense to a less optically dense medium