Combined Science Double Award - 9204 OxfordAQA

Sound

Gbogbo ọrọ náà

Hold a finger against your throat and hum. What you feel is the whole of this topic in one sensation: something is shaking, and because it is shaking you can hear it. Every sound that has ever reached you began as a vibration and arrived as a vibration, carried across the room by air that squashes and stretches hundreds or thousands of times a second without ever travelling anywhere itself. Take the air away and the vibration has nothing to ride on, which is why the loudest explosion in space would reach you in complete silence.

This lesson takes that idea and turns it into physics you can calculate with. You will learn why a sound is high or low and why it is quiet or deafening, where the two limits of your own hearing sit, and what happens when a sound wave runs into a wall or squeezes through a doorway. You will learn to turn a clap and a stopwatch into a measurement of the speed of sound, and to run the wave equation both ways for a sound wave you cannot hear. There are only three statements in this topic and every one of them is Core Tier, so whichever tier you are entered for, all of it is yours to know.

Ebumnobi

Sound waves are longitudinal waves and cause vibrations in a medium, which are detected as sound. The range of human hearing is about 20 Hz to 20 000 Hz. No details of the structure of the ear are required.
The pitch of a sound is determined by the frequency of vibrations of the source. Its loudness is related to the size of the amplitude of the disturbance.
Sound waves can be reflected (echoes) and diffracted.

Maapụ uche

E seela isiokwu a ka ị hụ otu echiche si ejikọta.

Mepee maapụ uche na ngwa

Akwụkwọ Ọmụmụ

A loudspeaker cone pushes forward and the air just in front of it has nowhere to go, so it becomes momentarily crowded. The cone pulls back and that same patch of air is left thinned out. Repeat that a few hundred times a second and a train of crowded and thinned regions sets off across the room at about 340 metres per second. Nothing has been sent anywhere: the same air molecules are still in front of the speaker, jiggling to and fro over a distance far smaller than the width of a hair. What travelled was the pattern, and the energy carried in it.

Ndetu Nkuzi Zuru Ezu di na Ngwa Green Bridge

Nweta ngwa Green Bridge CBT na ekwenti gi ma o bu kompiuta maka ulo akwukwo IGCSE zuru oke: akwukwo ule ndi gara aga, usoro nyocha, eserese uche, kaadi omumu na nkuzi olu.

Akwụkwọ ndụmọdụ zuru oke nwere eserese

Onye inyeaka mmụta AI

Ule nnwale nwere oge a na-ahazi ozugbo i mechara

Budata ngwa ekwentị Budata ngwa kọmputa

Ọ dị na Android, Windows, macOS, na Linux Ngwa iOS na-abia n'oge na-adighi anya

Nnyocha Ọmụmụ

Ekele diri gi maka imecha ihe karịrị na Sound. Ugbu a na ị na-enyochakwa isi echiche na echiche ndị dị mkpa, ọ bụ oge iji nwalee ihe ị ma. Ngwa a na-enye ụdị ajụjụ ọmụmụ dị iche iche emebere iji kwado nghọta gị wee nyere gị aka ịmata otú ị ghọtara ihe ndị a kụziri.

Ị ga-ahụ ngwakọta nke ụdị ajụjụ dị iche iche, gụnyere ajụjụ chọrọ ịhọrọ otu n’ime ọtụtụ azịza, ajụjụ chọrọ mkpirisi azịza, na ajụjụ ede ede. A na-arụpụta ajụjụ ọ bụla nke ọma iji nwalee akụkụ dị iche iche nke ihe ọmụma gị na nkà nke ịtụgharị uche.

Jiri akụkụ a nke nyocha ka ohere iji kụziere ihe ị matara banyere isiokwu ahụ ma chọpụta ebe ọ bụla ị nwere ike ịchọ ọmụmụ ihe ọzọ. Ekwela ka nsogbu ọ bụla ị na-eche ihu mee ka ị daa mba; kama, lee ha anya dị ka ohere maka ịzụlite onwe gị na imeziwanye.

What type of wave is a sound wave? A. A transverse wave B. A longitudinal wave C. An electromagnetic wave D. A wave that needs no medium Answer: B
What is the approximate range of frequencies that a human can hear? A. 2 Hz to 2000 Hz B. 20 Hz to 20 000 Hz C. 200 Hz to 200 000 Hz D. 20 000 Hz to 2 000 000 Hz Answer: B
A guitar string is plucked harder but is not shortened or retuned. What happens to the sound? A. It becomes louder and higher in pitch B. It becomes louder with the pitch unchanged C. It becomes higher in pitch with the loudness unchanged D. It becomes quieter and lower in pitch Answer: B
A student stands 100 m from a wall and claps. She hears the echo 0.60 s later. What is the speed of sound in air from her measurement? A. 60 m/s B. 167 m/s C. 333 m/s D. 600 m/s Answer: C
Why can you hear a person speaking round the corner of a solid wall but not see them? A. Sound travels faster than light B. Sound has a wavelength comparable to the wall and diffracts appreciably, while light has a far shorter wavelength and diffracts negligibly C. Sound is a transverse wave and light is longitudinal D. Sound is reflected by the wall and light is absorbed by it Answer: B

Rue ajuju ndi a n'ime ngwa ahu