Frékuénsi
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Keur kagunaan séjén, tempo Frékuénsi (disambiguasi).
Frékuénsi nyaéta pangukuran jumlah wanci dimana hiji kajadian nu dibalikan lumangsung per unit wanci. Didéfinisikeun ogé minangka rarata parobahan fase wangun galura sinusoidal.
Daptar eusi |
[édit] Pangukuran
Keur ngitung frékuénsi hiji event, itung heula jumlah occurrence event salila interval wanci nu tetep, terus bagi ku panjang interval wancina.
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Artikel ieu keur dikeureuyeuh, ditarjamahkeun tina basa Inggris. Bantosanna diantos kanggo narjamahkeun. |
In SI units, the result is measured in hertz (Hz), named after the German physicist Heinrich Rudolf Hertz. 1 Hz means that an event repeats once per second, 2 Hz is twice per second, and so on. This unit was originally called a cycle per second (cps), which is still used sometimes. Other units that are used to measure frequency include revolutions per minute (rpm) and radians per second (rad/s). Heart rate and musical tempo are measured in beats per minute (BPM).
An alternative method to calculate frequency is to measure the time between two consecutive occurrences of the event (the period) and then compute the frequency f as the reciprocal of this time:
where T is the period. A more accurate measurement takes many cycles into account and averages the period between each.
[édit] Frékuénsi galura
Frequency has an inverse relationship to the concept of wavelength. The frequency f is equal to the speed v of the wave divided by the wavelength λ (lambda) of the wave:
In the special case of electromagnetic waves moving through a vacuum, then v = c, where c is the speed of light in a vacuum, and this expression becomes:
When waves travel from one medium to another, their frequency remains exactly the same — only their wavelength and speed change.
Apart from being modified by the Doppler effect, frequency is an invariant quantity in the universe. That is, it cannot be changed by any physical process unlike velocity of propagation or wavelength.
[édit] Conto
- The frequency of the standard pitch A above middle C is usually defined as 440 Hz, that is, 440 cycles per second (Listen ) and known as concert pitch, to which an orchestra tunes.
- A baby can hear tones with oscillations up to approximately 20,000 Hz, but these frequencies become more difficult to hear as people age.
- In Europe, the frequency of the alternating current in mains is 50 Hz (close to the tone G), however, in North America, the frequency of the alternating current is 60 Hz (close to the tone B flat — that is, a minor third above the European frequency). The frequency of the 'hum' in an audio recording can show where the recording was made — in Europe or in America.
[édit] Tempo ogé
- Frékuénsi négatif
- Konvérter frékuénsi
- Letter frequencies
