Wave Velocity vs Wave Frequency
Wave tshaj tawm thiab nthwv dej zaus yog ob yam tseem ceeb ntawm nthwv dej. Lub nthwv dej tshaj tawm piav qhia tias lub zog nthuav tawm sai npaum li cas. Lub yoj zaus piav qhia tias lub nthwv dej nrawm npaum li cas oscillating. Ob qho ntawm cov khoom no tseem ceeb heev hauv kev txhais thiab piav txog lub nthwv dej. Kev paub zoo hauv cov ntsiab lus no yuav tsum tau ua kom ua tau zoo hauv thaj chaw xws li classical mechanics, quantum mechanics thiab txawm tias yooj yim teb xws li acoustics. Hauv tsab xov xwm no, peb yuav tham txog dab tsi yoj zaus thiab nthwv dej tshaj tawm yog, lawv cov ntsiab lus, qhov zoo sib xws ntawm yoj tshaj tawm thiab nthwv dej zaus, thiab thaum kawg qhov sib txawv ntawm yoj tshaj tawm thiab nthwv dej zaus.
Wave Frequency
Frequency yog ib lub tswv yim sib tham hauv ntu ntu ntawm cov khoom. Yuav kom nkag siab txog lub tswv yim ntawm zaus, yuav tsum muaj kev nkag siab zoo ntawm cov lus tsa suab. Ib qho lus tsa suab tuaj yeem suav tias yog ib qho kev txav uas rov ua nws tus kheej hauv lub sijhawm teem tseg. Lub ntiaj teb revolving ib ncig ntawm lub hnub yog ib tug periodic motion. Lub satellite orbiting nyob ib ncig ntawm lub ntiaj teb yog ib tug periodic motion; txawm tias cov lus tsa suab ntawm lub pob sib npaug yog ib qho kev txav mus los. Feem ntau ntawm cov lus tsa suab peb ntsib yog ncig, linear lossis semi-circular. Ib qho kev txav mus los muaj ntau zaus. Qhov zaus txhais tau tias "ntau npaum li cas" qhov kev tshwm sim. Rau qhov yooj yim, peb siv zaus raws li qhov tshwm sim ib ob. Cov lus tsa suab ib ntus tuaj yeem ua ib yam lossis tsis sib xws. Cov khaub ncaws hnav tuaj yeem muaj qhov sib txawv ntawm qhov nrawm nrawm. Cov haujlwm xws li amplitude modulation tuaj yeem muaj ob lub sijhawm. Lawv yog cov haujlwm ua ntu zus nyob rau hauv lwm cov haujlwm raws sijhawm. Lub yoj zaus yog ib qho cuab yeej txiav txim siab los ntawm qhov chaw ntawm nthwv dej. Rau nthwv dej xws li lub teeb thiab lub suab, qhov zaus ntawm nthwv dej nyob twj ywm tib yam tsis hais qhov nruab nrab nws mus.
Wave Velocity
Wave tshaj tawm yog qhov nrawm uas nthwv dej nthuav tawm hauv nruab nrab. Wave velocity yog ib yam khoom ntawm qhov nruab nrab. Qhov no tuaj yeem piav qhia los ntawm lub sijhawm impedance. Impedance yog qhov tsis kam ntawm qhov nruab nrab rau kev nthuav tawm ntawm nthwv dej. Ib qho nruab nrab nrog impedance siab dua yuav ua rau nthwv dej txav qeeb dua thaum lub nruab nrab nrog qis impedance yuav ua rau nthwv dej mus nrawm dua. Kev sib txuas ntawm yoj tshaj tawm thiab nthwv dej zaus yog muab los ntawm qhov sib npaug nto moo V=f λ, qhov twg V yog qhov nrawm nrawm, f yog qhov zaus ntawm nthwv dej, thiab λ yog qhov wavelength. Lub impedance ntawm qhov nruab nrab kuj nyob ntawm qhov zaus ntawm nthwv dej.
Qhov txawv ntawm Wave Velocity thiab Wave Frequency yog dab tsi?
• Wave velocity yog tus nqi tshaj tawm, uas ntsuas hauv meters ib ob. Wave zaus yog tus nqi zaus, uas ntsuas hauv hertz.
• Wave velocity yog ib yam khoom ntawm qhov nruab nrab rau ib hom nthwv dej. Lub yoj zaus yog ib qho cuab yeej txiav txim los ntawm qhov zaus ntawm qhov chaw.
• Wave zaus nyob twj ywm tsis hais qhov nruab nrab ntawm qhov nthwv dej tab tom taug kev. Wave velocity hloov nrog qhov nruab nrab. Qhov kev hloov pauv hauv nthwv dej no ua rau kev soj ntsuam xws li refraction.
