Doppler Effect - Key terms



AMPLITUDE:

The maximum displacement of a vibrating material. In wave motion, amplitude is the "size" of a wave, an indicator of the energy and intensity of the wave.

CYCLE:

One complete oscillation. In wave motion, this is equivalent to the movement of a wave from trough to crest and back to trough. For a sound wave, in particular, a cycle is one complete vibration.

DOPPLER EFFECT:

The change in the observed frequency of a wave when the source of the wave is moving with respect to the observer. It is named after Austrian physicist Johann Christian Doppler (1803-1853), who discovered it.

FRAME OF REFERENCE:

The perspective an observer has with regard to an object or action. Frame of reference affect sperception of various physical properties, and plays a significant role in the Dopplereffect.

FREQUENCY:

In wave motion, frequency is the number of waves passing through a given point during the interval of one second. The higher the frequency, the shorter the wavelength. Measured in Hertz, frequency is mathematically related to wave speed, wavelength, and period.

HARMONIC MOTION:

The repeated movement of a particle about a position of equilibrium, or balance.

HERTZ:

A unit for measuring frequency, named after nineteenth-century German physicist Heinrich Rudolf Hertz (1857-1894). High frequencies are expressed in terms of kilohertz (kHz; 10 3 or 1,000 cycles per second); megahertz (MHz; 10 6 or 1 million cycles per second);and gigahertz (GHz; 10 9 or 1 billion cycles per second.)

INTENSITY:

Intensity is the rate at which a wave moves energy per unit of cross-sectional area. Where sound wavesare concerned, intensity is commonly known as "volume."

OSCILLATION:

A type of harmonic motion, typically periodic, in one or more dimensions.

PERIOD:

For wave motion, a period is the amount of time required to complete one full cycle. Period is mathematically related to frequency, wavelength, and wave speed.

PERIODIC MOTION:

Motion that is repeated at regular intervals. These intervals are known as periods.

PERIODIC WAVE:

A wave in which a uniform series of crests and troughs follow one after the other in regular succession.

RELATIVE MOTION:

The motion of one object in relation to another.

WAVELENGTH:

The distance between a crest and the adjacent crest, or the trough and an adjacent trough, of a wave. Wavelength, symbolized λ (the Greek letter lambda) is mathematically related to wave speed, period, and frequency.

WAVE MOTION:

A type of harmonic motion that carries energy from one place to another without actually moving anymatter.

Also read article about Doppler Effect from Wikipedia

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