Frequency - definition of frequency by The Free Dictionary Frequency - definition of frequency by The Free Dictionary n. pl. fre·quen·cies 1. The property or condition of occurring at frequent intervals. 2. Mathematics & Physics The number of times a specified periodic phenomenon occurs within a specified interval, as: a. The number of repetitions of a complete sequence of values of a periodic function per unit variation of an independent variable. b. The number of complete cycles of a periodic process occurring per unit time. c. The number of repetitions per unit time of a complete waveform, as of an electric current. 3. Statistics [Latin frequentia, multitude, from frequēns, frequent-, crowded, numerous, frequent.] frequency n, pl -cies 1. the state of being frequent; frequent occurrence 2. the number of times that an event occurs within a given period; rate of recurrence 3. (Mathematics) physics the number of times that a periodic function or vibration repeats itself in a specified time, often 1 second. It is usually measured in hertz. Symbol: ν or f 4. (Statistics) statistics a. the number of individuals in a class (absolute frequency) b.

the ratio of this number to the total number of individuals under survey (relative frequency) 5. (Biology) ecology a. the number of individuals of a species within a given area b. the percentage of quadrats that contains individuals of a species Also called (for senses 1, 2): frequence [C16: from Latin frequentia a large gathering, from frequēns numerous, crowded] fre•quen•cy 1. Also, fre′quence. the state or fact of being frequent; frequent occurrence. 2. rate of occurrence. 3. Physics. a. the number of periods or regularly occurring events of any given kind in a unit of time, usu. one second. b. the number of cycles or completed alternations per unit time of a wave or oscillation. Symbol: F; Abbr.: freq. 4. Math. the number of times a value recurs in a unit change of the independent variable of a given function. 5. Statistics. the number of items occurring in a given category. [1545–55; < Latin] fre·quen·cy (frē′kwən-sē) 1.

Physics The number of complete cycles of a wave, such as a radio wave, that occur per second. See more at wave . 2. Mathematics The ratio of the number of occurrences of some event to the number of opportunities for its occurrence. Frequency (See also DURATION , TIME .) once in a blue moon Very rarely. A blue moon occurs when there is a full moon twice in the same month, an unusual event, but one that takes place from time to time. rare as hen’s teeth See scarce as hen’s teeth, ABSENCE . when two Fridays come together Never. Since two Fridays never come together, this expression is usually used as a sarcastic quip when one is asked when he intends to do something of an onerous nature such as complete a project, pay back a personal loan, or the like. frequency Number of cycles or waves per second. ThesaurusAntonymsRelated WordsSynonymsLegend: Noun 1.

frequency - the number of occurrences within a given time period; "the frequency of modulation was 40 cycles per second"; "the frequency of his seizures increased as he grew older" audio frequency , audio - an audible acoustic wave frequency radio frequency - an electromagnetic wave frequency between audio and infrared infrared , infrared frequency - the infrared region of the electromagnetic spectrum; electromagnetic wave frequencies below the visible range; "they could sense radiation in the infrared" wave number - the reciprocal of the wavelength of a wave attendance - the frequency with which a person is present; "a student's attendance is an important factor in her grade" count per minute , counts/minute - frequency per minute sampling frequency - (telecommunication) the frequency of sampling a continuously varying signal rate - a magnitude or frequency relative to a time unit; "they traveled at a rate of 55 miles per hour"; "the rate of change was faster than expected" 2. frequency - the ratio of the number of observations in a statistical category to the total number of observations ratio - the relative magnitudes of two quantities (usually expressed as a quotient) incidence , relative incidence - the relative frequency of occurrence of something 3.

cardinal number , cardinal - the number of elements in a mathematical set; denotes a quantity but not the order frequency noun recurrence , repetition , constancy , periodicity , commonness , frequentness , prevalence The cars broke down with increasing frequency. Translations high/low frequency → alta/ baja frecuencia B. CPD frequency band N → banda f de frecuencia frequency distribution N (Statistics) → distribución f de frecuencia frequency modulation N → frecuencia f modulada frequency to increase in frequency → être de plus en plus fréquent (e) (PHYSICS) [sound wave] → fréquence ffrequency modulation n → modulation f de fréquence frequency n → Häufigkeit f; (Phys) → Frequenz f; high/low frequency → Hoch-/Niederfrequenz f frequency frequent (ˈfriːkwənt) adjective happening often. He made frequent journeys.

gereelde مُتَكَرِّر чест frequente častý häufig hyppig; jævnlig συχνός frecuente sagedane مکرر usein toistuva fréquent תכוף अक्सर cest, ucestal gyakori sering tíður frequente たびたびの 자주 일어나는 dažnas biežs sering frequent hyppig , stadig częsty مکرر frequente frecvent частый častý pogost čest ofta förekommande ซึ่งเป็นประจำ sık sık olan 時常發生的 частий اکثر thường xuyên; hay xảy ra 时常发生的 (friˈkwent) verb to visit often. He used to frequent the George Hotel.

dikwels besoek يزور تِكرارا посещавам често frequentar často navštěvovat oft aufsuchen besøge hyppigt; frekventere συχνάζω frecuentar sageli külastama همیشه رفتن به vierailla usein fréquenter לְבָקֵר תְּכוּפוֹת ב- बारबार जाना posjecivati, pohadati gyakran ellátogat (vhová) sering mengunjungi stunda, sækja frequentare ～によく行く 자주 가다 dažnai lankyti(s) bieži apmeklēt sering mengunjungi regelmatig bezoeken vanke i , besøke ofte , frekventere często bywać په وار وار يا دعادت له مخه يوه ځاى ته ورتلل frequentar a frecventa часто посещать často chodiť (do) biti reden gost često

 posećivati frekventera ไปเป็นประจำ sık (sık) gitmek 常去 часто відвідувати اکثر جانا hay lui tới hoặc thăm một nơi nào đó 常去 ˈfrequency – plural ˈfrequencies – noun 1.

the state of happening often. The frequency of her visits surprised him.

gereeldheid تَكْرار повтаряне frequência častost die Häufigkeit hyppighed συχνότητα frecuencia sagedus تکرار yleisyys fréquence תָדִירוּת גבוֹהָה आवृत्‍ति ucestalost gyakoriság kekerapan tíðleiki frequenza ひんぱん 빈발 dažnumas biežums kekerapan frequentie hyppighet , hyppig forekomst częstość فرى كوينسى، وار وار پيښيدنه، تكرار، سرعت، په برق كى دبرېښنا دجريان ددوران شمير چه دمتناوب جريان در لودونكى ماشين په ذريعه په يوه ثانيه كى واقع كيږى: په فزيك كى اهتزاز اتو شمير دوخت په يوه واحد كى frequência regularitate частота častosť pogostnost učestalost t

ät förekomst, ideligt upprepande ความบ่อย sıklık 頻繁 частота بار بار کرنا یا ہونا tính thường xuyên; tính thường hay xảy ra 频繁 2.

(in electricity, radio etc) the number of waves, vibrations etc per second. At what frequency does the sound occur? frekwensie تَرَدُّد честота frequência frekvence, kmitočet die Schwingungszahl, die Frequenz frekvens συχνότητα frecuencia sagedus بسامد taajuus fréquence תדר बारम्बारता frekvencija frekvencia frekuensi tíðni frequenza 周波数 진동 횟수 dažnis frekvence frekuensi frequentie frekvens , svingningstall częstotliwość د امواجو شمير frequência frecvenţă частота kmitočet frekvenca frekvencija frekvens, svängningstal ความถี่ frekans 周率 частотність آواز کی حامل لہروں کا اتار چڑھاؤ tần số 周率 3. a set wavelength on which radio stations regularly broadcast.

I regularly listen to this frequency in order to hear my favourite music.

frekwensie ذَبْذَبَه честота frequência frekvence die Frequenz frekvens; bølgelængde συχνότητα , μήκος κύματος frecuencia sagedus فرکانس taajuus fréquence תדר फ्रेक्वेन्सी radijska frekvencija frekvencia frekuensi, gelombang bylgjulengd, tíðni frequenza 周波数 주파수 dažnis frekvence gelombang frequentie frekvens częstotliwość فرى كوينسى frequência frecvenţă частота frekvencia frekvenca frekvencija frekvens คลื่นความถี่ dalga , frekans 頻率 частота لہروں کا ایک خاص حجم جس پر کوئی ریڈیو اسٹیشن نشریات بھیجتا ہے dải tần 频率 ˈfrequently adverb often. He frequently arrived late.

gereeld تِكْراراً често frequentemente často häufig hyppigt; jævnligt συχνά frecuentemente tihti اغلب usein fréquemment לְעִתִים קְרוֹבוֹת बहुधा cesto gyakran sering oft, tíðum frequentemente ひんぱんに 자주 dažnai bieži sering vaak hyppig , ofte , stadig często په واروار، په مكرر ډول frequentemente (în mod) frecvent часто často pogosto često ofta, titt och tätt บ่อย ๆ sık sık 經常地 часто اکثر thường xuyên 经常地 frequency Cycles per second - definition of Cycles per second by The Free Dictionary Cycles per second - definition of Cycles per second by The Free Dictionary n. pl. fre·quen·cies 1. The property or condition of occurring at frequent intervals. 2. Mathematics & Physics The number of times a specified periodic phenomenon occurs within a specified interval, as: a.

The number of repetitions of a complete sequence of values of a periodic function per unit variation of an independent variable. b. The number of complete cycles of a periodic process occurring per unit time. c. The number of repetitions per unit time of a complete waveform, as of an electric current. 3. Statistics [Latin frequentia, multitude, from frequēns, frequent-, crowded, numerous, frequent.] frequency n, pl -cies 1. the state of being frequent; frequent occurrence 2. the number of times that an event occurs within a given period; rate of recurrence 3. (Mathematics) physics the number of times that a periodic function or vibration repeats itself in a specified time, often 1 second. It is usually measured in hertz. Symbol: ν or f 4. (Statistics) statistics a. the number of individuals in a class (absolute frequency) b. the ratio of this number to the total number of individuals under survey (relative frequency) 5. (Biology) ecology a. the number of individuals of a species within a given area b.

the percentage of quadrats that contains individuals of a species Also called (for senses 1, 2): frequence [C16: from Latin frequentia a large gathering, from frequēns numerous, crowded] fre•quen•cy 1. Also, fre′quence. the state or fact of being frequent; frequent occurrence. 2. rate of occurrence. 3. Physics. a. the number of periods or regularly occurring events of any given kind in a unit of time, usu. one second. b. the number of cycles or completed alternations per unit time of a wave or oscillation. Symbol: F; Abbr.: freq. 4. Math. the number of times a value recurs in a unit change of the independent variable of a given function. 5. Statistics. the number of items occurring in a given category. [1545–55; < Latin] fre·quen·cy (frē′kwən-sē) 1. Physics The number of complete cycles of a wave, such as a radio wave, that occur per second. See more at wave . 2. Mathematics The ratio of the number of occurrences of some event to the number of opportunities for its occurrence.

Frequency (See also DURATION , TIME .) once in a blue moon Very rarely. A blue moon occurs when there is a full moon twice in the same month, an unusual event, but one that takes place from time to time. rare as hen’s teeth See scarce as hen’s teeth, ABSENCE . when two Fridays come together Never. Since two Fridays never come together, this expression is usually used as a sarcastic quip when one is asked when he intends to do something of an onerous nature such as complete a project, pay back a personal loan, or the like. frequency Number of cycles or waves per second. ThesaurusAntonymsRelated WordsSynonymsLegend: Noun 1.

frequency - the number of occurrences within a given time period; "the frequency of modulation was 40 cycles per second"; "the frequency of his seizures increased as he grew older" audio frequency , audio - an audible acoustic wave frequency radio frequency - an electromagnetic wave frequency between audio and infrared infrared , infrared frequency - the infrared region of the electromagnetic spectrum; electromagnetic wave frequencies below the visible range; "they could sense radiation in the infrared" wave number - the reciprocal of the wavelength of a wave attendance - the frequency with which a person is present; "a student's attendance is an important factor in her grade" count per minute , counts/minute - frequency per minute sampling frequency - (telecommunication) the frequency of sampling a continuously varying signal rate - a magnitude or frequency relative to a time unit; "they traveled at a rate of 55 miles per hour"; "the rate of change was faster than expected" 2. frequency - the ratio of the number of observations in a statistical category to the total number of observations ratio - the relative magnitudes of two quantities (usually expressed as a quotient) incidence , relative incidence - the relative frequency of occurrence of something 3.

cardinal number , cardinal - the number of elements in a mathematical set; denotes a quantity but not the order frequency noun recurrence , repetition , constancy , periodicity , commonness , frequentness , prevalence The cars broke down with increasing frequency. Translations high/low frequency → alta/ baja frecuencia B. CPD frequency band N → banda f de frecuencia frequency distribution N (Statistics) → distribución f de frecuencia frequency modulation N → frecuencia f modulada frequency to increase in frequency → être de plus en plus fréquent (e) (PHYSICS) [sound wave] → fréquence ffrequency modulation n → modulation f de fréquence frequency n → Häufigkeit f; (Phys) → Frequenz f; high/low frequency → Hoch-/Niederfrequenz f frequency frequent (ˈfriːkwənt) adjective happening often. He made frequent journeys.

gereelde مُتَكَرِّر чест frequente častý häufig hyppig; jævnlig συχνός frecuente sagedane مکرر usein toistuva fréquent תכוף अक्सर cest, ucestal gyakori sering tíður frequente たびたびの 자주 일어나는 dažnas biežs sering frequent hyppig , stadig częsty مکرر frequente frecvent частый častý pogost čest ofta förekommande ซึ่งเป็นประจำ sık sık olan 時常發生的 частий اکثر thường xuyên; hay xảy ra 时常发生的 (friˈkwent) verb to visit often. He used to frequent the George Hotel.

dikwels besoek يزور تِكرارا посещавам често frequentar často navštěvovat oft aufsuchen besøge hyppigt; frekventere συχνάζω frecuentar sageli külastama همیشه رفتن به vierailla usein fréquenter לְבָקֵר תְּכוּפוֹת ב- बारबार जाना posjecivati, pohadati gyakran ellátogat (vhová) sering mengunjungi stunda, sækja frequentare ～によく行く 자주 가다 dažnai lankyti(s) bieži apmeklēt sering mengunjungi regelmatig bezoeken vanke i , besøke ofte , frekventere często bywać په وار وار يا دعادت له مخه يوه ځاى ته ورتلل frequentar a frecventa часто посещать často chodiť (do) biti reden gost često

 posećivati frekventera ไปเป็นประจำ sık (sık) gitmek 常去 часто відвідувати اکثر جانا hay lui tới hoặc thăm một nơi nào đó 常去 ˈfrequency – plural ˈfrequencies – noun 1.

the state of happening often. The frequency of her visits surprised him.

gereeldheid تَكْرار повтаряне frequência častost die Häufigkeit hyppighed συχνότητα frecuencia sagedus تکرار yleisyys fréquence תָדִירוּת גבוֹהָה आवृत्‍ति ucestalost gyakoriság kekerapan tíðleiki frequenza ひんぱん 빈발 dažnumas biežums kekerapan frequentie hyppighet , hyppig forekomst częstość فرى كوينسى، وار وار پيښيدنه، تكرار، سرعت، په برق كى دبرېښنا دجريان ددوران شمير چه دمتناوب جريان در لودونكى ماشين په ذريعه په يوه ثانيه كى واقع كيږى: په فزيك كى اهتزاز اتو شمير دوخت په يوه واحد كى frequência regularitate частота častosť pogostnost učestalost t

ät förekomst, ideligt upprepande ความบ่อย sıklık 頻繁 частота بار بار کرنا یا ہونا tính thường xuyên; tính thường hay xảy ra 频繁 2.

(in electricity, radio etc) the number of waves, vibrations etc per second. At what frequency does the sound occur? frekwensie تَرَدُّد честота frequência frekvence, kmitočet die Schwingungszahl, die Frequenz frekvens συχνότητα frecuencia sagedus بسامد taajuus fréquence תדר बारम्बारता frekvencija frekvencia frekuensi tíðni frequenza 周波数 진동 횟수 dažnis frekvence frekuensi frequentie frekvens , svingningstall częstotliwość د امواجو شمير frequência frecvenţă частота kmitočet frekvenca frekvencija frekvens, svängningstal ความถี่ frekans 周率 частотність آواز کی حامل لہروں کا اتار چڑھاؤ tần số 周率 3. a set wavelength on which radio stations regularly broadcast.

I regularly listen to this frequency in order to hear my favourite music.

frekwensie ذَبْذَبَه честота frequência frekvence die Frequenz frekvens; bølgelængde συχνότητα , μήκος κύματος frecuencia sagedus فرکانس taajuus fréquence תדר फ्रेक्वेन्सी radijska frekvencija frekvencia frekuensi, gelombang bylgjulengd, tíðni frequenza 周波数 주파수 dažnis frekvence gelombang frequentie frekvens częstotliwość فرى كوينسى frequência frecvenţă частота frekvencia frekvenca frekvencija frekvens คลื่นความถี่ dalga , frekans 頻率 частота لہروں کا ایک خاص حجم جس پر کوئی ریڈیو اسٹیشن نشریات بھیجتا ہے dải tần 频率 ˈfrequently adverb often. He frequently arrived late.

gereeld تِكْراراً често frequentemente často häufig hyppigt; jævnligt συχνά frecuentemente tihti اغلب usein fréquemment לְעִתִים קְרוֹבוֹת बहुधा cesto gyakran sering oft, tíðum frequentemente ひんぱんに 자주 dažnai bieži sering vaak hyppig , ofte , stadig często په واروار، په مكرر ډول frequentemente (în mod) frecvent часто často pogosto često ofta, titt och tätt บ่อย ๆ sık sık 經常地 часто اکثر thường xuyên 经常地 frequency Frequency and Period of a Wave The Physics Classroom » Physics Tutorial » Waves » Frequency and Period of a Wave Waves - Lesson 2 - Properties of a Wave Frequency and Period of a Wave The Wave Equation The nature of a wave was discussed in Lesson 1 of this unit.

In that lesson, it was mentioned that a wave is created in a slinky by the periodic and repeating vibration of the first coil of the slinky. This vibration creates a disturbance that moves through the slinky and transports energy from the first coil to the last coil. A single back-and-forth vibration of the first coil of a slinky introduces a pulse into the slinky. But the act of continually vibrating the first coil with a back-and-forth motion in periodic fashion introduces a wave into the slinky. Suppose that a hand holding the first coil of a slinky is moved back-and-forth two complete cycles in one second. The rate of the hand's motion would be 2 cycles/second. The first coil, being attached to the hand, in turn would vibrate at a rate of 2 cycles/second. The second coil, being attached to the first coil, would vibrate at a rate of 2 cycles/second. The third coil, being attached to the second coil, would vibrate at a rate of 2 cycles/second. In fact, every coil of the slinky would vibrate at this rate of 2 cycles/second.

This rate of 2 cycles/second is referred to as the frequency of the wave. The frequency of a wave refers to how often the particles of the medium vibrate when a wave passes through the medium. Frequency is a part of our common, everyday language. For example, it is not uncommon to hear a question like "How frequently do you mow the lawn during the summer months?" Of course the question is an inquiry about how often the lawn is mowed and the answer is usually given in the form of "1 time per week." In mathematical terms, the frequency is the number of complete vibrational cycles of a medium per a given amount of time. Given this definition, it is reasonable that the quantity frequency would have units of cycles/second, waves/second, vibrations/second, or something/second. Another unit for frequency is the Hertz (abbreviated Hz) where 1 Hz is equivalent to 1 cycle/second. If a coil of slinky makes 2 vibrational cycles in one second, then the frequency is 2 Hz. If a coil of slinky makes 3 vibrational cycles in one second, then the frequency is 3 Hz.

And if a coil makes 8 vibrational cycles in 4 seconds, then the frequency is 2 Hz (8 cycles/4 s = 2 cycles/s). The quantity frequency is often confused with the quantity period. Period refers to the time that it takes to do something. When an event occurs repeatedly, then we say that the event is periodic and refer to the time for the event to repeat itself as the period. The period of a wave is the time for a particle on a medium to make one complete vibrational cycle. Period, being a time, is measured in units of time such as seconds, hours, days or years. The period of orbit for the Earth around the Sun is approximately 365 days; it takes 365 days for the Earth to complete a cycle. The period of a typical class at a high school might be 55 minutes; every 55 minutes a class cycle begins (50 minutes for class and 5 minutes for passing time means that a class begins every 55 minutes). The period for the minute hand on a clock is 3600 seconds (60 minutes); it takes the minute hand 3600 seconds to complete one cycle around the clock.

Frequency and period are distinctly different, yet related, quantities. Frequency refers to how often something happens. Period refers to the time it takes something to happen. Frequency is a rate quantity. Period is a time quantity. Frequency is the cycles/second. Period is the seconds/cycle. As an example of the distinction and the relatedness of frequency and period, consider a woodpecker that drums upon a tree at a periodic rate. If the woodpecker drums upon a tree 2 times in one second, then the frequency is 2 Hz. Each drum must endure for one-half a second, so the period is 0.5 s. If the woodpecker drums upon a tree 4 times in one second, then the frequency is 4 Hz; each drum must endure for one-fourth a second, so the period is 0.25 s. If the woodpecker drums upon a tree 5 times in one second, then the frequency is 5 Hz; each drum must endure for one-fifth a second, so the period is 0.2 s. Do you observe the relationship? Mathematically, the period is the reciprocal of the frequency and vice versa. In equation form, this is expressed as follows.

Since the symbol f is used for frequency and the symbol T is used for period, these equations are also expressed as: The quantity frequency is also confused with the quantity speed. The speed of an object refers to how fast an object is moving and is usually expressed as the distance traveled per time of travel. For a wave, the speed is the distance traveled by a given point on the wave (such as a crest) in a given period of time. So while wave frequency refers to the number of cycles occurring per second, wave speed refers to the meters traveled per second. A wave can vibrate back and forth very frequently, yet have a small speed; and a wave can vibrate back and forth with a low frequency, yet have a high speed. Frequency and speed are distinctly different quantities. Wave speed will be discussed in more detail later in this lesson . Investigate! How do changes in the frequency of a wave affect the wavelength of a wave? Use the Wave plotter widget below to find out. Alter the frequency and observe how the pattern changes. Period and Frequency About Watch and Favorite Watch Watching this resources will notify you when proposed changes or new versions are created so you can keep track of improvements that have been made.

Favorite Favoriting this resource allows you to save it in the “My Resources” tab of your account. There, you can easily access this resource later when you’re ready to customize it or assign it to your students. Period and Frequency The period is the duration of one cycle in a repeating event, while the frequency is the number of cycles per unit time. Learning Objective Practice converting between frequency and period Key Points Motion that repeats itself regularly is called periodic motion. One complete repetition of the motion is called a cycle. The duration of each cycle is the period . The frequency refers to the number of cycles completed in an interval of time. It is the reciprocal of the period and can be calculated with the equation f=1/T. Some motion is best characterized by the angular frequency (ω). The angular frequency refers to the angular displacement per unit time and is calculated from the frequency with the equation ω=2πf. Terms The quotient of the number of times n a periodic phenomenon occurs over the time t in which it occurs: f = n / t. Example A Victorian parlor trick was to listen to the pitch of a fly's buzz, reproduce the musical note on the piano, and announce how many times the fly's wings had flapped in one second.

If the fly's wings flap, say, 200 times in one second, then the frequency of their motion is f=200/1 s=200 Hz. The period is one 200th of a second, T=1/f=(1/200) s=0.005 s. Full Text Period and Frequency The usual physics terminology for motion that repeats itself over and over is periodic motion, and the time required for one repetition is called the period, often expressed as the letter T. (The symbol P is not used because of the possible confusion with momentum . ) One complete repetition of the motion is called a cycle. The frequency is defined as the number of cycles per unit time. Frequency is usually denoted by a Latin letter f or by a Greek letter ν (nu). Note that period and frequency are reciprocals of each other . Sinusoidal waves of various frequencies; the bottom waves have higher frequencies than those above. The horizontal axis represents time. $f = 1/T$ For example, if a newborn baby's heart beats at a frequency of 120 times a minute, its period (the interval between beats) is half a second.

If you calibrate your intuition so that you expect large frequencies to be paired with short periods, and vice versa, you may avoid some embarrassing mistakes on physics exams. Units In SI units , the unit of frequency is the hertz (Hz), named after the German physicist Heinrich Hertz: 1 Hz indicates that an event repeats once per second. A traditional unit of measure used with rotating mechanical devices is revolutions per minute, abbreviated RPM. 60 RPM equals one hertz (i.e., one revolution per second, or a period of one second). The SI unit for period is the second. Angular Frequency Often periodic motion is best expressed in terms of angular frequency, represented by the Greek letter ω (omega). Angular frequency refers to the angular displacement per unit time (e.g., in rotation) or the rate of change of the phase of a sinusoidal waveform (e.g., in oscillations and waves), or as the rate of change of the argument of the sine function. Frequency - Credo Reference Topic Page: Frequency Definition: frequency from Collins Dictionary of Astronomy Symbol: f, ν. The number of oscillations per unit time of a vibrating system. Frequency is measured in hertz.

The frequency of a wave is the number of wave crests passing a point per unit time. For light and other electromagnetic radiation, it is related to wavelength λ by ν = c/λ, where c is the speed of light. Summary Article: frequency from The Hutchinson Unabridged Encyclopedia with Atlas and Weather Guide Image from: electromagnetic spectrum Spanning from short,... in Astronomy Encyclopedia In physics, number of periodic oscillations, vibrations, or waves occurring per unit of time. The SI unit of frequency is the hertz (Hz), one hertz being equivalent to one cycle per second. Frequency is related to wavelength and velocity by the equation: f = v/λ where f is frequency, v is velocity, and λ is wavelength. Frequency is the reciprocal of the periodT: f = 1/T The electrical mains supply in the UK is AC (alternating current) with a frequency of 50 Hz. Each time the current changes direction, the voltage falls to zero before increasing again as the current moves in the opposite direction. At 50 Hz, the current will change direction 100 times a second.

At one end of the electromagnetic spectrum are long radio waves with a frequency below 105 Hz and at the other extreme are gamma rays with a frequency beyond 1019 Hz. Human beings can hear sounds from objects vibrating in the range 20–15,000 Hz. Ultrasonic frequencies well above 15,000 Hz can be detected by such mammals as bats. Infrasound (low-frequency sound) can be detected by some mammals and birds. Pigeons can detect sounds as low as 0.1 Hz; elephants communicate using sounds as low as 1 Hz. Frequency modulation (FM) is a method of transmitting radio signals in which the frequency of the carrier wave is changed and then decoded. One kilohertz (kHz) equals 1,000 hertz; one megahertz (MHz) equals 1,000,000 hertz. essays Waves Review - with Answers Categories of Waves 4. A transverse wave is traveling through a medium. See diagram below. The particles of the medium are vibrating _____. a. parallel to the line joining AD. b. along the line joining CI. c. perpendicular to the line joining AD.

d. at various angles to the line CI. e. along the curve CAEJGBI. Answer: A In transverse waves, particles of the medium vibrate to and from in a direction perpendicular to the direction of energy transport. In this case, that would be parallel to the line AD. Useful Web Links [ #1 | #2 | #3 | #4 | #5 | #6 | #7 | #8 | #9 | #10 | #11 | #12 | #13 | #14 | #15 | #16 | #17 | #18 | #19 | #20 | #21 | #22 | #23 | #24 | #25 | #26 | #27 | #28 | #29 | #30 | #31 | #32 | #33 | #34 | #35 | #36 | #37 | #38 ] 5. If the energy in a longitudinal wave travels from south to north, the particles of the medium would be vibrating _____. a. from north to south, only b. both north and south c.

from east to west, only d. both east and west Answer: B In longitudinal waves, particles of the medium vibrate to and from in a direction parallel to the direction of energy transport. If the particles only moved north and not back south, then the particles would be permanently displaced from their rest position; this is not wavelike. Useful Web Links [ #1 | #2 | #3 | #4 | #5 | #6 | #7 | #8 | #9 | #10 | #11 | #12 | #13 | #14 | #15 | #16 | #17 | #18 | #19 | #20 | #21 | #22 | #23 | #24 | #25 | #26 | #27 | #28 | #29 | #30 | #31 | #32 | #33 | #34 | #35 | #36 | #37 | #38 ] 25. Two different ropes with different mass densities are attached to each other. A pulse is introduced into one end of the rop and approaches the boundary as shown at the right.

At the boundary, a portion of the energy is transmitted into the new medium and a portion is reflected. Which one of the diagrams below depicts the possible location and orientation of the pulse shortly after the incident pulse reaches the boundary? Answer: C The speeds in the two media can be deduced by the distance of the pulses from the boundary. In A and E, the speed is shown as fastest on the right, which makes the transmitted medium the less dense. Rule out A and E since a reflected pulse should not invert when moving from more dense to less dens. Rule out B for just the opposite reasons; the wave is moving from less to more dense and should invert upon reflection. Rule out D because the transmitted pulse never inverts. That leaves C as the answer.

Useful Web Links [ #1 | #2 | #3 | #4 | #5 | #6 | #7 | #8 | #9 | #10 | #11 | #12 | #13 | #14 | #15 | #16 | #17 | #18 | #19 | #20 | #21 | #22 | #23 | #24 | #25 | #26 | #27 | #28 | #29 | #30 | #31 | #32 | #33 | #34 | #35 | #36 | #37 | #38 ] 27. Diagram P at the right shows a transverse pulse traveling along a dense rope toward its junction with a less dense rope. Which of the diagrams (A, B, C, D, or E) below depicts the ropes at the instant that the reflected pulse again passes through its original position marked X? Consider such features as amplitude and relative speed (i.e., the relative distance of the transmitted and reflected pulses from boundary).

Answer: E A, B, and C can be quickly ruled out since it shows the amplitude of the reflected and incident pulse to be the same size. An incident pulse would give up some of its energy to the transmitted pulse at the boundary, thus making the amplitude of the reflected pulse less than that of the incident pulse. Rule out D since it shows the reflected pulse moving faster than the transmitted pulse. This would not happen unless moving from less dense to more dense. This leaves E as the answer. Useful Web Links [ #1 | #2 | #3 | #4 | #5 | #6 | #7 | #8 | #9 | #10 | #11 | #12 | #13 | #14 | #15 | #16 | #17 | #18 | #19 | #20 | #21 | #22 | #23 | #24 | #25 | #26 | #27 | #28 | #29 | #30 | #31 | #32 | #33 | #34 | #35 | #36 | #37 | #38 ] 29.

The diagram at the right shows a disturbance moving through a rope towards the right. If this disturbance meets a similar disturbance moving to the left, then which one of the diagrams below depict a pattern which could NEVER appear in the rope? Answer: D WOW! Tough one. Draw a second wave to the right of the wave which is given. Then visually move the wave to the left. Visualize in your mind the shape of the resultant as interference occurs. It will never look like D. If you still don't get it, take a break and watch some TV.

Useful Web Links [ #1 | #2 | #3 | #4 | #5 | #6 | #7 | #8 | #9 | #10 | #11 | #12 | #13 | #14 | #15 | #16 | #17 | #18 | #19 | #20 | #21 | #22 | #23 | #24 | #25 | #26 | #27 | #28 | #29 | #30 | #31 | #32 | #33 | #34 | #35 | #36 | #37 | #38 ] 30. A 2.0-meter long rope is hanging vertically from the ceiling and attached to a vibrator. A single pulse is observed to travel to the end of the rope in 0.50 s. What frequency should be used by the vibrator to maintain three whole waves in the rope? a.

0.75 Hz [ #1 | #2 | #3 | #4 | #5 | #6 | #7 | #8 | #9 | #10 | #11 | #12 | #13 | #14 | #15 | #16 | #17 | #18 | #19 | #20 | #21 | #22 | #23 | #24 | #25 | #26 | #27 | #28 | #29 | #30 | #31 | #32 | #33 | #34 | #35 | #36 | #37 | #38 ] 36. Two pulses are traveling in opposite directions along the same medium as shown in the diagram at the right. Which diagram below best depicts the appearance of the medium when each pulse meets in the middle? Answer: D When a crest is completely overlapped with a trough having the same amplitude, destructive interference occurs. Complete cancellation takes place if they have the same shape and are completely overlapped. Useful Web Links Frequency dictionary definition | frequency defined From Latin frequentia, from frequens.

frequency - Computer Definition The Institute of Electrical and Electronics Engineers (IEEE) defines frequency as the number of complete cycles of sinusoidal variation per unit time, with the unit of time generally being that of one second. Plotting y = sin x, where x is expressed in radians, yields a sine wave as illustrated in Figure F-8. (From the Latin radius, a radian is a unit of plane angular measurement equivalent to the angle between two radii that enclose a section of a circle's circumference [arc] equal in length to the length of a radius.There are 2 radians in a circle.) A complete sine wave entails a cycle as measured from a point of zero (0) amplitude to a point of maximum positive amplitude (+A), through zero to a point of maximum negative amplitude ( The number of oscillations (vibrations) in one second. Frequency is measured in Hertz (Hz), which is the same as "oscillations per second" or "cycles per second." For example, the alternating current in a wall outlet in the U.S. and Canada is 60Hz. Electromagnetic radiation is measured in kiloHertz (kHz), megahertz (MHz) and gigahertz (GHz).

See wavelength , frequency response , audio , carrier and space/time . Frequency The frequency is the number of oscillations per second. The higher the frequency (the closer the ripples would be in this diagram) and the shorter the wavelength. Oscillating Systems MASS ON A SPRING (return to start of page) l = the extension produced when the mass m is attached to the spring. If the mass is pulled a little further down and released, it will oscillate about its equilibrium position. At a distance x from equilibrium, the mass experiences a ï¿½restoring forceï¿½ F, i.e. one trying to force it back to the equilibrium position. The constant k is called the ï¿½spring constantï¿½ of the spring (ï¿½ k = F/x, unit Nm-1) We see from F = kx that the bigger the value of k the bigger the force F needed to get a given extension x. Thus, k is a measure of the stiffness of the spring, i.e. a measure of how hard it is to stretch (or compress) it. The expression F = kx gives the magnitude of the restoring force.

when the mass is below the equilibrium position F points upwards when the mass is above the equilibrium position F points downwards So, wherever the mass is, the force always acts towards the same point, the equilibrium point. We can take the relative directions of F and x into account by writing: F and a have the same direction as each other, and are always opposite to x: Now, in the above equation for acceleration a, (k/m) is a positive constant for a given spring and mass, so the equation is of the form: Thus, a mass oscillating on a spring satisfies the conditions for SHM. The mass oscillates just like the point N in the earlier analysis. The power ï¿½ï¿½ï¿½ representing ï¿½square-rootï¿½ of the content of the brackets. In the position shown in (b) for the mass-spring system above, the mass is at its equilibrium position. In this position: Where, l = original extension produced when the mass m is hung on the spring. Show that PE = KE when x = A/ï¿½2, as indicated above.

Energy in a spring In both an oscillating pendulum and a mass-spring system there is a continuous exchange between PE and KE. If the oscillations are 'free', then the sum of these is constant, and is given by: For a mass-spring system, we can express this in terms of the spring constant k. This equals the energy when the spring is stretched to its maximum, i.e. when the extension equals the amplitude, A. Now, the strain energy stored in a spring when it is stretched by an amount A by a force F is given by: Damping A free vibration is one which continues with constant amplitude, neither gaining nor losing energy. For such an oscillation a displacement (x) against time (t) curve might look like: An oscillation that loses its energy is said to be damped. a) Light damping FORCED VIBRATIONS AND RESONANCE (return to start of page) A system that can vibrate, such as a pendulum or a mass on a spring, has a natural period, this being the period with which it vibrates if it is set in motion and then left to oscillate. It also has a corresponding natural frequency. Some systems have a number of natural periods/frequencies.

When you push a child's swing you automatically push it, i.e. apply a forcing vibration, in time with its own natural period, and this allows the amplitude of the swing to build up. This is an example of resonance. Resonance is said to occur when a system is forced to vibrate at its own natural frequency, and this can produce large amplitude vibrations Observation

Question: What can be expressed as the number of cycles of a vibration occurring per unit of time?
Answer: Frequency