Terms in this set (45)

  • Mechanical waves
    Rhythmic disturbances of a medium: sound waves, water waves, etc.
  • Electromagnetic waves
    Energy in wave form that is capable of traveling through a vacuum: radio waves, microwaves, etc.
  • Crests
    The highest point on a wave
  • Troughs
    The lowest point on a wave
  • Amplitude
    The distance that a wave rises or falls from its normal rest position
  • Wavelength
    The distance between adjacent troughs or peaks
  • Frequency
    The number of waves that pass a given point in one second
  • Hertz
    The unit of frequency; one cycle per second
  • Velocity
    The rate at which an object changes position in a specified direction
  • Transverse wave
    A wave whose vibration is at right angles to the direction in which it is traveling
  • Longitudinal wave
    A wave whose vibration is in the same direction that it is traveling
  • Constructive interference
    The inphase reinforcement of waves as they pass through each other
  • Destructive interference
    The out-of-phase cancellation of waves as they pass through each other
  • Radio waves
    Electromagnetic waves with wavelengths between 1 and 10 m long and with frequencies below those of visible light waves
  • Microwaves
    Electromagnetic waves with wavelengths from .3 cm, and with frequencies that range from 10(9th power) Hz to 10(11th power) Hz
  • Radar
    Radio detection and ranging devices that detect objects through the transmission and reflection of microwaves off of surfaces
  • Infrared waves
    Electromagnetic waves with frequencies lower than visible light but greater than radio waves
  • Prism
    A triangular block of glass that is used to separate visible light into various colors
  • Incandescent light
    Heated and glowing light
  • Ultraviolet light
    Electromagnetic waves that are just beyond visible light in frequency
  • X rays
    Electromagnetic waves with frequencies higher than ultraviolet light; strong enough to penetrate tissues
  • Gamma rays
    A form of radiation consisting of high-energy electromagnetic waves; electromagnetic waves that originate in the nucleus of an atom; the type of electromagnetic waves with the highest frequencies
  • Visible light
    The portion of radiant energy that can be sensed by our eyes
  • Line spectrum
    A display of the various frequencies of light emitted by a source
  • Additive primary colors
    Red, blue, and green; form various colors when mixed in different proportions
  • Subtractive primary colors
    Yellow, cyan, and magenta; when mixed in various proportions, they absorb all other colors except the one that is reflected
  • Intensity
    The measure of how bright the light from a light source is or the loudness of sound
  • Candela
    The metric unit of light intensity
  • Beam
    A very large number of individual light waves
  • Rays
    Representations of the directions of light waves
  • Normal
    An imaginary line drawn perpendicular to the surface of a mirror
  • Incident ray
    A incoming ray (toward the reflecting surface)
  • Reflected ray
    An outgoing ray (away from the reflecting surface)
  • Angle of incidence
    The angle between the incident ray and the normal
  • Angle of reflection
    The angle between the reflected ray and the normal
  • Law of reflection
    The angle of incidence must be equal to the angle of reflection
  • Plane mirror
    A flat mirror
  • Virtual images
    The images that appear to exist beyond a mirror
  • Concave mirrors
    A mirror that curves like the inner surface of a sphere
  • Principal focus
    A point through which the rays reflected or refracted from a surface will pass
  • Real image
    An image that is produced in front of the plane of a mirror
  • Refraction
    The bending of waves as they pass from one medium into another
  • Lens
    A transparent object that uses the property of refraction to magnify or reduce images
  • Focal length
    The distance from a lens to its principal focus
  • Dispersion
    The separation of white light into different-colored light waves