Longitudinal wave

particle motion and wave velocity are parallel (e.g. sound waves)

Transverse wave

particle motion is perpendicular to the direction of the wave velocity (e.g. light/EM waves)

Sound

the propagation of longitudinal waves through matter

Sound spectrum

Infrasonic (less than 20 Hz) Audible (20 Hz to 20 kHz) Ultrasonic (greater than 20 kHz)

Sound intensity

rate of sound energy transfer through a given area; measured in W/m^2 (J/s/m^2); expressed in decibels

Doppler effect

the apparent shortening of wavelength and increase in frequency as a source approaches and lengthening of wavelength and decrease in frequency as the source moves away; also applies to light with redshift (as source is moving away) and blueshift (as source approaches)

Standing waves

caused by interference of waves traveling down and reflected back along a rope

Resonance

oscillations with large amplitudes that occur when a periodic driving force has a frequency equal to a natural frequency

Reflection

a change in direction that occurs when light bounces off of a surface

Law of reflection

The angle of reflection is equal to the angle of incidence

Refraction

light bending when it passes from one medium to another

Index of refraction

index of refraction = speed of light in a vacuum / speed of light in a medium

Internal reflection

light bouncing back and forth within a material (e.g. what happens with fiber optics and diamonds)

Critical angle

if an incident ray is at an angle greater than this, the light will be reflected internally, not refracted out into another medium

Dispersion

occurs when different wavelengths of light are bent at slightly different angles during refraction (white light going through a prism and dispersing into a spectrum of colors)

Polarization

the preferential orientation of the oscillations of transverse waves (forcing light to only go one direction), cannot happen to longitudinal waves like sound, only to transverse waves

Diffraction

the bending of a wave that occurs when it is faced with an obstacle, happens to all types of waves

Principle of superposition

at any time, the combined waveform of two or more interfering waves is given by the sum of the displacements of the individual waves at each point in the medium

Constructive interference

when multiple waves overlap/interfere and combine to form a bigger wave

Destructive interference

when two waves interfere and the combined waveform is smaller than either of the pulses

Electric force

exists between any two charged particles; the attractive or repulsive force on the particles based on the law of charges

Law of charges

Like charges repel, unlike charges attract

Coulomb's Law

the force of attraction between two charged bodies is directly proportional to the product of the two charges and inversely proportional to the square of the distance between them F = kq1q2 / r^2

Current

the time rate of flow of electric charge

Conductor

materials in which electric charge flows readily

Insulator

materials in which electrons are more tightly bound and do not conduct electrical charge very well

Voltage

work per unit charge, or, the electric potential energy per unit of charge

Ohm's Law

voltage equals current times resistance (V = IR)

Electrical power

power equals current x voltage (P = IV) OR power equals current squared x resistance (P = I^2R)

Magnetism

closely related to electricity, caused by moving and spinning electrons

Curie temperature

temperature at which a material ceases to be ferromagnetic

Magnetic declination

the angle between true (geographic) north and magnetic north

Electromagnetism

interaction of electrical and magnetic effects, consist of oscillating electric and magnetic fields

Motor

a device that converts electrical energy into mechanical energy

Generator

a device that converts mechanical energy into electrical energy