vibrate
move back and forth rapidly
variable
something that can change or vary in an investigation
pitch
how high or low a note is
wave
a transfer of energy with no net transfer of mass
medium
the material through which a wave can travel
periodic wave
a repetitive series of pulses; a wave sequence in which the particles of the medium undergo periodic motion; that s after a fixed time the medium returns to its starting point then repeats
crest
the highest point of displacement of a wave
trough
the lowest point of displacement of a wave
amplitude
the maximum displacement of a particle as a wave passes the height of a wave crest; it is related to the waves energy
wavelength
the distance between two identical points of a wave
frequency
the number of waves produced per unit time
period
the time required to complete one cycle of a wave
transverse wave
a wave in which the medium is perpendicular to the motion of the wave
longitudinal wave
a wave in which the motion of the medium is parallel to the direction of the motion of the wave
standing wave
a wave pattern that remains in a constant position
node
a point on a standing wave where the medium is motionless
antinode
a point on a standing wave where the displacement is the largest
inverse relationship
a relationship in which decreasing one variable increases the other variable or vise versa
direct relationship
a relationship in which increasing one variable increases the other or vise versa
umbra
the part of the shadow that gets no light
penumbra
the part of the shadow that gets partial light
angle of incidence
the angle formed between an incident ray and the normal
angle of reflection
the angle formed between a reflected ray and the normal
incident ray
the ray of light that strikes a surface
reflected ray
the yat of light that reflects off a surface
normal
a line that is perpendicular
law of relfection
a law for mirrors that states that the angle of incidence is equal to the angle of reflection