College Physics for AP® Courses

# Glossary

amplitude
the maximum displacement from the equilibrium position of an object oscillating around the equilibrium position
antinode
the location of maximum amplitude in standing waves
beat frequency
the frequency of the amplitude fluctuations of a wave
constructive interference
when two waves arrive at the same point exactly in phase; that is, the crests of the two waves are precisely aligned, as are the troughs
critical damping
the condition in which the damping of an oscillator causes it to return as quickly as possible to its equilibrium position without oscillating back and forth about this position
deformation
displacement from equilibrium
destructive interference
when two identical waves arrive at the same point exactly out of phase; that is, precisely aligned crest to trough
elastic potential energy
potential energy stored as a result of deformation of an elastic object, such as the stretching of a spring
force constant
a constant related to the rigidity of a system: the larger the force constant, the more rigid the system; the force constant is represented by k
frequency
number of events per unit of time
fundamental frequency
the lowest frequency of a periodic waveform
intensity
power per unit area
longitudinal wave
a wave in which the disturbance is parallel to the direction of propagation
natural frequency
the frequency at which a system would oscillate if there were no driving and no damping forces
nodes
the points where the string does not move; more generally, nodes are where the wave disturbance is zero in a standing wave
oscillate
moving back and forth regularly between two points
over damping
the condition in which damping of an oscillator causes it to return to equilibrium without oscillating; oscillator moves more slowly toward equilibrium than in the critically damped system
overtones
multiples of the fundamental frequency of a sound
period
time it takes to complete one oscillation
periodic motion
motion that repeats itself at regular time intervals
resonance
the phenomenon of driving a system with a frequency equal to the system's natural frequency
resonate
a system being driven at its natural frequency
restoring force
force acting in opposition to the force caused by a deformation
simple harmonic motion
the oscillatory motion in a system where the net force can be described by Hooke’s law
simple harmonic oscillator
a device that implements Hooke’s law, such as a mass that is attached to a spring, with the other end of the spring being connected to a rigid support such as a wall
simple pendulum
an object with a small mass suspended from a light wire or string
superposition
the phenomenon that occurs when two or more waves arrive at the same point
transverse wave
a wave in which the disturbance is perpendicular to the direction of propagation
under damping
the condition in which damping of an oscillator causes it to return to equilibrium with the amplitude gradually decreasing to zero; system returns to equilibrium faster but overshoots and crosses the equilibrium position one or more times
wave
a disturbance that moves from its source and carries energy
wave velocity
the speed at which the disturbance moves. Also called the propagation velocity or propagation speed
wavelength
the distance between adjacent identical parts of a wave