# Shared Flashcard Set

## Details

Oscillations and Waves
N/A
45
Physics
12/12/2011

Term
 *Displacement (for waves)
Definition
 distance a particle moves in a particular direction from its mean (equilibrium) position
Term
 *Ampltitude
Definition
 maximum displacement from the mean position
Term
 *Frequency (f)
Definition
 number of oscillations per unit time
Term
 *Period (T)
Definition
 time taken for one complete oscillation (cycle) (OR: time taken for one cycle to pass a given point)
Term
 *Phase Difference
Definition
 difference in phase between two points
Term
 *Simple Harmonic Motion
Definition
 motion that takes place when the acceleration of an object is proportional to its displacement from its equilibrium position and is always directed toward its equilibrium position (NOTE: this motion is defined by the equation a = -ω2x)
Term
 Damping
Definition
 involves a force that is always in the opposite direction to the direction of motion of the oscillating particle (NOTE: this force is a dissipative force)
Term
 Critical Damping
Definition
 when a resistive force is applied to an oscillating system that causes the particle to return to zero displacement in a minimum amount of time
Term
 Natural Frequency of Vibration
Definition
 when a system is displaced from equilibrium and allowed to oscillate freely, it will do so at its natural frequency of vibration
Term
 Forced Oscillations
Definition
 a system may be forced to oscillate at any given frequency by an outside driving force that is applied to it
Term
 *Resonance
Definition
 a transfer of energy in which a system is subject to an oscillating force that matches the natural frequency of the system resulting in a large amplitude of vibration
Term
 *Wave Pulse
Definition
 single oscillation or disturbance in a medium
Term
 *Continuous Progressive Wave
Definition
 series of periodic pulses (NOTE: involves a transfer of energy) (NOTE: each point on the wave has the same amplitude)
Term
 *Transverse Wave
Definition
 wave in which the direction of motion of the energy transfer (the wave) is perpendicular to the direction of motion of the particles of the medium (NOTE: light waves are transverse) (NOTE: transverse waves cannot be propagated in gases)
Term
 *Longitudinal Wave
Definition
 wave in which the direction of motion of the energy transfer (the wave) is parallel to the direction of motion of the particles of the medium (NOTE: sound waves are longitudinal)
Term
 Wavefront
Definition
 collection of neighboring points on a wave that are in phase
Term
 Ray
Definition
 line drawn perpendicular to a wavefront indicating the direction of motion of the energy transfer
Term
 Crest
Definition
 top of a transverse wave
Term
 Trough
Definition
 bottom of a transverse wave
Term
 Compression
Definition
 area of high pressure in a longitudinal wave
Term
 Rarefraction
Definition
 area of high pressure in a longitudinal wave
Term
 *Wavelength(λ)
Definition
 shortest distance along the wave between two points in phase with one another (OR: distance traveled by the wave in one period)
Term
 *Wave speed (v)
Definition
 speed of transfer of the energy of the wave
Term
 *Intensity
Definition
 power received per unit area (NOTE: for a wave, its intensity is proportional to the square of its amplitude)
Term
 Law of Reflection
Definition
 The angle of incidence is equal to the angle of reflection when both angles are measured with respect to the normal line
Term
 *Snell's Law
Definition
 The angle of incidence is equal to the angle of reflection when both angles are measured with respect to the normal line
Term
 *Refractive Index (n)
Definition
 a. the ratio of the speed of the wave in the refracted medium to the speed of the wave in the incident medium.b. the ratio of the sine of the angle of incidence to the sine of the angle of refraction
Term
 Diffraction
Definition
 the bending of a wave around an obstacle or the spreading of a wave through an opening (NOTE: diffraction is only noticeable when the size of the opening is smaller than or on the same order of the size of the wavelength)
Term
 *Principle of Superposition
Definition
 When two waves meet, the resultant displacement is the vector sum of the displacements of the component waves.
Term
 Constructive Interference
Definition
 superposition of two waves which are in phase with each other
Term
 Destructive Interference
Definition
 superposition of two waves which are out of phase with each other
Term
 Path Difference
Definition
 difference in the distances two waves must travel from their sources to a given point
Term
 Standing (stationary) wave
Definition
 resultant wave formed when two waves of equal amplitude and frequency traveling in opposite directions in the same medium interfere (NOTE: does not involve a transfer of energy) (NOTE: points on the wave have varying amplitudes)
Term
 *Node
Definition
 locations of constant complete destructive interference on a standing wave
Term
 *Antinode
Definition
 locations of maximum constructive interference on a standing wave
Term
 Fundamental (First Harmonic)
Definition
 lowest frequency mode of vibration of a standing wave
Term
 *Doppler Effect
Definition
 The change of frequency of a wave due to the movement of the source or the observer relative to the medium of wave transmission.
Term
 Resolution
Definition
 ability to distinguish between two sources of light
Term
 *Rayleigh Criterion
Definition
 When the central maximum of one diffraction pattern overlaps the first minimum of a second diffraction pattern, the two sources are “just resolved.”
Term
 *Polarized Light
Definition
 light in which the electric field vector vibrates in one plane only
Term
 *Brewster's Law
Definition
 When light is incident on a surface at such an angle that the reflected and transmitted rays are perpendicular and the reflected ray is totally plane polarized, then the index of refraction of the substance is equal to the tangent of the angle of incidence. (n = tan θi)
Term
 *Polarizer
Definition
 device that produces plane polarized light from an unpolarized beam
Term
 *Analyzer
Definition
 polarizer used to detect polarized light
Term
 Malus' Law
Definition
 the transmitted intensity of polarized light is equal to the product of the incident intensity times the square of the cosine of the angle between the direction of the analyzer and the direction of the electric field vibration of the polarized light (I = Io cos2 θ )
Term
 Optically Active Substance
Definition
 one that rotates the plane of polarization of the light that passes through it (OR: one that changes the plane in which the electric field vector of the light vibrates)
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