frequency - Copy.docx

7/24/2019 frequency - Copy.docx

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Frequency

Frequencyis the number of occurrences of a repeating event

per unit time.

If there is a pattern or cycle, the number it occurs in a period of

time is the frequency.

The unit for frequency is Hertz (Hz), named after the scientist

Heinrich Hertz. He was a Germanphysicistwho first conclusively proved

the existence of electromagnetic wavestheorized by James Clerk

Maxwell's electromagnetic theory of light !ertz proved the theory

by engineeringinstruments to transmit and receive radiopulses

using experimental proceduresthat ruled outall other known wireless

phenomena "he unit of fre#uency $ cycle per second$ was named the

%hertz% in his honor

It is also referred to as temporal frequency, which emphasizes

the contrast to spatial frequency and angular frequency.

In mathematics, physics, and engineering, spatial frequencyis

a characteristic of any structure that is periodic across position

in space.

h

ttp!!ucalgary.ca!pip"#$!mod%!spatial!frequency&

In spatial frequency, it is more of property of the light. It shows

how it creates more detail the higher the frequency the picture or

the image has.


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In physics, angular frequency' (also referred to by the

terms angular speed, radial frequency, circular

frequency, orbital frequency,radian frequency,

and pulsatance) is a scalar measure of rotation rate.

https!!upload.wiimedia.org!wiipedia!co

mmons!c!c$!ngular*requency.gif

In angular frequency, it is the number of cycle occurrence in a

period of time.

*or e+ample, the cloc, the thinnest hand of the " arm clocs

rotates fastest. In one minute, one rotation occurs.

& minute #- seconds


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& rotation 360

1 rotation

1minute x

1minute

60 secondsx

360

1rotation=

360

60 seconds=6Hz

*requency describes the number of waves that pass a +ed place

in a given amount of time. /o if the time it taes for a wave to

pass is&!0 second, the frequency is 0 per second. If it taes &!&--

of an hour, the frequency is &-- per hour.

http!!www.qrg.northwestern.edu!pro1ects!vss!docs!communications!&2what2is2frequency.html

This photo shows how frequency wors through waves. The high

frequency radio waves create more wavelength or cycle in a

period of time, while the low frequency waves create less number

of wavelength or cycle.


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*or e+ample in 3 seconds, the high frequency will create &--

cycles meaning f 0- Hz. 4hile the low would only do 3- for 3

seconds meaning f &- Hz. It shows the di5erence between the

high and low frequency based on the number of cycle they

create.

The periodis the duration of time of one cycle in a repeating

event, so the period is the reciprocal of the frequency.

*rom the latter e+ample, it shows that reciprocating the time is

equivalent to the frequency proving the equation

f=1

t

whereas

f frequency

t time


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https!!upload.wiimedia.org!wiipedia!com

mons!3!3$!*requencynimation.gif

This photo shows the how the frequency wors through the use of

6ashing circles beside the measurements. It also shows the reversely

proportional of frequency vs. time.

Sound

*requency is the property of sound that most determines pitch.

Pitchis a perceptual property of sounds that allows their

ordering on a frequency2related scale, or more commonly, pitch is

the quality that maes it possible to 1udge sounds as 7higher7 and

7lower7 in the sense associated with musical melodies.


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http!!imgur.com!owz89*

This is a photo of a violin:s string pluced in slow motion. It shows

the di5erences of frequencies in each string. ;luc the thicest

string and it will create a number of wavelength, pluc the

thinnest string with the same energy or force applied to the thicstring and it will create the same number of wavelength but on a

shorter period of time. This e+plains that the higher the pitch

produced, the higher the frequency is. lso showing that the

faster the vibration is, the higher the higher the frequency and

the pitch is.

The frequencies an ear can hear are limited to a specic range of

frequencies.


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https!!upload.wiimedia.org!wiipedia!commons!c!c%!th2byage.png

This tells us the di5erence of how humans receive the sounds.

The frequency is the intensity of sound being pro1ected while the

sound pressure is how strong our ears receive it. The older you

are, the more sensitive you become that is why the samefrequency sends to your ear but strong in sound pressure is

received, depending on age.

The audible frequency range for humans is typically given as

being between about 0- Hz and 0-,--- Hz (0- Hz), though the

high frequency limit usually reduces with age.


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http!!hyperte+tboo.com!facts!0--"!Tim=ondon.shtml

The picture shows the di5erences of how much frequency

di5erent species can tolerate. /ome animals can tolerate up to

&-- >Hz lie bats, it may be a benet to hear lighter sounds but it

also maes their ears more sensitive to loud noises.


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?eferences

https!!en.wiipedia.org!wii!*requency@citeAnote2&

http!!www.qrg.northwestern.edu!pro1ects!vss!docs!communicatio

ns!&2what2is2frequency.html

http!!hyperte+tboo.com!facts!0--"!Tim=ondon.shtml

http!!ucalgary.ca!pip"#$!mod%!spatial!frequency&

9uestions

&. The frequency is AAAAA of time.

a. Bquivalentb. ?eciprocalc. 8easurementd. 8edium

0. *requency is the property of sound that most determines

AAAAAA.a. 8elodyb. 4avelengthc. Cibrationd. ;itch

". The audible frequency range for humans is typically betweenabout AAAAAAAA.a. 0-Hz and 0--,--- Hzb. 0-Hz and 0-,--- Hzc. 0 Hz and 0,--- Hzd. 0- Hz and 0,--- Hz

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frequency - Copy.docx