Frequency: Difference between revisions
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imported>Anthony Argyriou (clarify frequency/wavelength relationship and frequency/energy relationship) |
imported>Milton Beychok m (Copy edits) |
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'''Frequency''' is a property of an oscillation, [[vibration]], or other regularly-repeating phenomenon. The frequency of such a phenomenon is the number of repetitions in a unit [[time]]. In the [[SI]] system of units, frequency is measured in [[Hertz]] ('''Hz'''), the number of repetitions in one [[second]]. | '''Frequency''' is a property of an [[oscillation]], [[vibration]], or other regularly-repeating (cyclic) phenomenon. The frequency of such a phenomenon is the number of repetitions (cycles) in a unit of [[time]]. In the [[SI]] system of units, frequency is measured in [[Hertz]] ('''Hz'''), the number of repetitions in one [[second]]. | ||
The frequency of vibrations is inversely proportional to [[wavelength]], which is a length measurement | The frequency ( '''''f''''' ) of vibrations is inversely proportional to [[wavelength]] ( '''''λ''''' ), which is a length measurement: | ||
:<math>\lambda = \frac{c}{f} \,\!</math>, where c is the speed of propagation of waves in the medium, or, for [[electromagnetic radiation]], c = 299 792 458 m/s, the [[speed of light]]. | |||
:<math>\lambda = \frac{c}{f} \,\!</math>, where '''''c''''' is the speed of propagation of waves in the medium, or, for [[electromagnetic radiation]], '''''c''''' = 299 792 458 m/s, the [[speed of light]]. | |||
In electromagnetic radiation, the [[energy]] of the vibration is proportional to the frequency: | In electromagnetic radiation, the [[energy]] of the vibration is proportional to the frequency: | ||
:<math>E=hf \,\!</math> , where h = 6.626 x 10<sup>-34</sup> J•s ([[Planck's constant]]) | :<math>E=hf \,\!</math> , where '''''h''''' = 6.626 x 10<sup>-34</sup> J•s ([[Planck's constant]]) | ||
Revision as of 14:46, 8 March 2010
Frequency is a property of an oscillation, vibration, or other regularly-repeating (cyclic) phenomenon. The frequency of such a phenomenon is the number of repetitions (cycles) in a unit of time. In the SI system of units, frequency is measured in Hertz (Hz), the number of repetitions in one second.
The frequency ( f ) of vibrations is inversely proportional to wavelength ( λ ), which is a length measurement:
- , where c is the speed of propagation of waves in the medium, or, for electromagnetic radiation, c = 299 792 458 m/s, the speed of light.
In electromagnetic radiation, the energy of the vibration is proportional to the frequency:
- , where h = 6.626 x 10-34 J•s (Planck's constant)
