Cov Lus Nug Piv Txwv Txog Cov Ntsiab Cai ntawm Wave
Cov nthwv dej yog cov xwm txheej ntawm lub cev uas ua lub luag haujlwm tseem ceeb hauv ntau yam ntawm lub neej txhua hnub thiab kev tshawb fawb. Kev nkag siab txog cov ntsiab cai yooj yim ntawm nthwv dej tso cai rau peb nkag siab zoo dua txog lub ntiaj teb nyob ib puag ncig peb. Hauv tsab xov xwm no, peb yuav tham txog ntau yam teeb meem piv txwv ntsig txog cov ntsiab cai nthwv dej tseem ceeb, xws li nthwv dej kho tshuab, nthwv dej hluav taws xob, thiab lwm yam xwm txheej cuam tshuam.
Kev Nkag Siab Yooj Yim Txog Cov Ncua Dej
Ib nthwv dej yog ib qho kev cuam tshuam uas kis mus rau hauv ib qho nruab nrab (xws li dej lossis cua) lossis qhov chaw. Cov nthwv dej tuaj yeem raug faib ua pawg raws li lawv kis mus li cas thiab qhov nruab nrab uas lawv taug kev hla. Ob pawg tseem ceeb yog cov nthwv dej mechanical, uas xav tau ib qho nruab nrab, thiab cov nthwv dej electromagnetic, uas tuaj yeem kis mus yam tsis muaj ib qho nruab nrab. Cov nthwv dej kuj tseem tuaj yeem raug faib ua nthwv dej transverse thiab longitudinal raws li kev coj ntawm cov khoom me me hauv qhov nruab nrab.
Piv txwv ntawm Cov Ntsiab Cai ntawm Wave
Lub Ntsiab Cai ntawm Kev Sib Sau Ua Ke
Lub hauv paus ntsiab lus ntawm kev sib tshooj hais tias thaum ob lossis ntau nthwv dej sib ntsib hauv ib qho nruab nrab, qhov cuam tshuam tshwm sim ntawm qhov ntawd yog qhov sib sau ua ke ntawm cov amplitudes ntawm txhua nthwv dej. Lub hauv paus ntsiab lus no yog qhov tseem ceeb rau kev nkag siab txog cov xwm txheej cuam tshuam.
Piv txwv teeb meem superposition:
Ob lub nthwv dej sinusoidal sib ntsib ntawm ib qho chaw saum npoo dej nrog qhov loj ntawm A1 = 3 cm thiab A2 = 4 cm. Yog tias ob lub nthwv dej no nyob rau hauv theem, txiav txim siab qhov loj ntawm lub nthwv dej uas tshwm sim.
Lus teb:
Vim tias ob lub nthwv dej nyob rau theem, qhov amplitude ntawm lub nthwv dej tshwm sim yog qhov sib npaug ntawm ob qho amplitudes:
\[ A_{\text{total}} = A_1 + A_2 = 3 \, \text{cm} + 4 \, \text{cm} = 7 \, \text{cm} \]
Txoj Cai Snell
Txoj cai ntawm Snell cuam tshuam txog kev cuam tshuam ntawm cov nthwv dej thaum lawv nkag mus rau hauv lwm qhov chaw, piv txwv li los ntawm huab cua mus rau dej. Qhov no yog qhia los ntawm cov qauv:
\[ n_1 \sin \theta_1 = n_2 \sin \theta_2 \]
qhov twg \(n_1\) thiab \(n_2\) yog cov ntsuas refractive ntawm nruab nrab 1 thiab 2, thiab \(\theta_1\) thiab \(\theta_2\) yog cov ces kaum ntawm qhov tshwm sim thiab refraction.
Cov Lus Nug Piv Txwv Txog Refraction:
Ib lub teeb ci ntsa iab los ntawm huab cua (refractive index = 1) thiab nkag mus rau hauv dej (refractive index = 1.33) ntawm lub kaum sab xis ntawm 30°. Txheeb xyuas lub kaum sab xis ntawm kev tawg hauv dej.
Lus teb:
Siv txoj cai Snell:
\[ 1 \cdot \sin(30^\circ) = 1.33 \cdot \sin(\theta_2) \]
\[ \sin(30^\circ) = 0.5 \]
\[ 0.5 = 1.33 \cdot \sin(\theta_2) \]
\[ \sin(\theta_2) = \frac{0.5}{1.33} \approx 0.376 \]
\[ \theta_2 = \sin^{-1}(0.376) \approx 22.2^\circ \]
Qhov Teeb Meem Diffraction
Diffraction yog qhov khoov ntawm cov nthwv dej thaum lawv ntsib cov teeb meem thiab hla dhau qhov sib txawv nqaim, nrog rau qhov xwm txheej no yuav pom tseeb dua yog tias qhov loj ntawm qhov sib txawv sib piv rau qhov wavelength.
Cov Lus Nug Piv Txwv Txog Diffraction:
Ib nthwv dej suab uas muaj qhov ntev ntawm 0,5 meters hla dhau ib qho qhov uas dav 1 meter. Sib tham txog seb qhov no yuav cuam tshuam li cas rau qhov diffraction ntawm nthwv dej.
Lus teb:
Vim tias qhov dav ntawm qhov slit loj dua qhov wavelength, cov nthwv dej suab yuav muaj kev diffraction, tab sis tsis ntau. Yog tias qhov dav ntawm qhov slit me dua lossis sib npaug rau qhov wavelength, qhov diffraction yuav pom tseeb dua.
Cov Ntxaib Hluav Taws Xob
Cov nthwv dej hluav taws xob (EM) suav nrog cov nthwv dej xov tooj cua, microwaves, teeb infrared, teeb pom kev, teeb ultraviolet, X-rays, thiab gamma rays. Tsis zoo li cov nthwv dej mechanical, cov nthwv dej EM tsis xav tau ib qho nruab nrab los nthuav dav.
Txoj Cai Planck
Qhov tshwm sim ntawm cov nthwv dej electromagnetic feem ntau tuaj yeem saib los ntawm qhov kev xav ntawm cov qauv niaj hnub no, xws li Planck txoj cai uas hais tias lub zog ntawm proton yog proportional rau nws qhov zaus:
\[ E = h \cdot f \]
qhov twg E yog lub zog, h yog Planck tus nqi tas mus li (6.626 \times 10^{-34} \, \text{Js}\)), thiab f yog zaus.
Cov Lus Nug Piv Txwv Txog Wave Electromagnetic:
Yog tias qhov zaus ntawm lub teeb ultraviolet yog \(8 \times 10^{14} \, \text{Hz}\), nws lub zog yog dab tsi?
Lus teb:
\[ E = 6.626 \times 10^{-34} \, \text{Js} \times 8 \times 10^{14} \, \text{Hz} = 5.301 \times 10^{-19} \, \text{J} \]
Kev kaw
Kev nkag siab txog cov ntsiab cai yooj yim ntawm cov nthwv dej yog qhov tseem ceeb rau kev kawm txog physics thiab nws cov kev siv hauv kev siv tshuab txhua hnub. Txij li cov ntsiab cai ntawm kev sib tshooj mus rau kev refraction mus rau diffraction, lawv muab kev nkag siab txog seb cov nthwv dej cuam tshuam nrog lawv ib puag ncig li cas thiab cuam tshuam rau cov xwm txheej uas peb pom.
Los ntawm cov piv txwv uas tau nthuav tawm, peb tuaj yeem nkag siab tob dua txog yuav ua li cas cov kev xav no tuaj yeem siv tau, thaum tseem ua kom peb nkag siab txog lub tswv yim ntawm nthwv dej. Hauv kev tshawb fawb siab heev, cov ntsiab cai no tseem siv tau rau hauv cov teb xws li kev sib txuas lus, optics, thiab txawm tias cosmology, ua rau lawv yog lub hauv paus tseem ceeb rau cov tub ntxhais kawm physics thiab cov kws tshawb fawb kom nkag siab.
