Wave

    Cards (16)

    • Wave is a disturbance that travels through a medium or a vacuum and carries energy
    • Wave train or periodic wave - a succession of periodic disturbances
    • Examples of waves in everyday life:
      • Light waves enable us to see
      • Sound waves allow us to hear
      • Radio waves transmit information
      • Microwaves are used in cell phone communication
      • Microwaves are used in microwave ovens for cooking
      • Ultrasound and X-rays are used in medical diagnosis
      • Ultraviolet rays are used to sterilize medical devices
      • A Slinky toy can be used to observe waves
    • Characteristics of waves:
      • Frequency: number of waves produced per unit time, measured in hertz (Hz)
      • Period: time for one complete cycle of a wave to pass a reference point, reciprocal of frequency. as a measure of time, is expressed in units of time, usually seconds.
      • Wavelength: distance between two successive points in phase with each other in a wave
      • Speed: distance traveled by a wave per unit time
      • Amplitude: maximum displacement of a particle on a medium from its resting position
    • Transverse waves:
      • Particles vibrate perpendicular to the direction of wave propagation
      • Consist of alternating hills and valleys
    • Longitudinal waves:
      • Particles vibrate parallel to the direction of wave propagation
      • Wavelength is the distance between consecutive rarefactions or compressions
    • Body waves:
      • Travel through Earth's interior
      • Divided into Primary waves (P waves) - longitudinal Secondary waves (S waves) - tranverse
    • Surface waves:
      • Travel on the surface of Earth
      • Love waves move the ground from side to side
      • Rayleigh waves move the ground up and down
    • Energy transmission by waves:
      • Waves transfer energy without significant particle movement
      • Energy is proportional to the square of amplitude
      • Energy is proportional to the square of frequency for mechanical waves
      • Energy of an electromagnetic wave depends on frequency and is inversely proportional to wavelength
    • Intensity of a wave:
      • Defined as energy transported per unit area and time
      • Inversely proportional to the square of the distance from the source (inverse square law)
    • Energy Transmission by Waves:
      Several factors affect the energy of a wave. Some of these factors are amplitude, frequency, wavelength, and distance.
    • Wave Pulse - single unrepeated disturbance
    • Mechanical Waves
      • requires a medium to propagate. Example of a mechanical wave is a sound wave. It cannot travel in a vacuum.
    • Electromagnetic Waves
      • Can travel in a vacuum and any medium.
      • Examples are radio waves, microwaves, infrared, visible light, ultraviolet, x-rays, and gamma rays
    • Transverse Wave
      • the particles of the medium vibrate perpendicular to the direction of wave propagation and consist of alternating hills and valleys
    • Longitudinal Wave
      • particles of the medium vibrate parallel to the direction of the wave propagation. In longitudinal waves, wavelength is the distance between any two consecutive rarefactions or any two consecutive compressions.