Tsab xov xwm hais txog Lub Zog Hluav Taws Xob
Txog qhov teeb meem ntawm lub zog hluav taws xob, tau kawm tias cov khoom zoo sib xws sib thawb ib leeg, thaum cov khoom tsis zoo sib xws rub ib leeg. Yog tias ib yam khoom uas muaj lub zog zoo raug coj los ze rau ib yam khoom uas muaj lub zog tsis zoo, ob yam khoom yuav rub ua ke kom lawv txav mus rau ib leeg. Ntawm qhov tod tes, yog tias ib yam khoom uas muaj lub zog zoo raug coj los ze rau ib yam khoom uas muaj lub zog zoo, ces ob yam khoom yuav thawb ib leeg kom lawv txav deb ntawm ib leeg. Raws li tau kawm txog Coulomb txoj cai, cov khoom uas muaj lub zog hluav taws xob tuaj yeem ua kom lwm yam khoom uas muaj lub zog hluav taws xob nrawm dua vim muaj lub zog hluav taws xob ua haujlwm ntawm cov khoom uas muaj lub zog hluav taws xob no. Lub zog hluav taws xob uas ib yam khoom uas muaj lub zog hluav taws xob ua rau lwm yam khoom uas muaj lub zog hluav taws xob yog ib qho piv txwv ntawm lub zog uas tuaj yeem ua yam tsis tau kov. Lwm qhov piv txwv ntawm lub zog uas tuaj yeem ua haujlwm ntawm qhov deb yog lub zog ntawm lub ntiajteb txawj nqus . Lub zog gravitational yog ib yam khoom loj ua rau lwm yam khoom loj.
Lub zog sib txhuam , lub zog thawb, lub zog ib txwm yog cov piv txwv ntawm cov zog uas yooj yim to taub vim tias cov zog no ua haujlwm thaum muaj kev sib cuag. Ntawm qhov tsis sib xws, lub zog hluav taws xob yog ib qho piv txwv ntawm lub zog uas nyuaj to taub vim tias lub zog no tuaj yeem ua haujlwm ntawm qhov deb yam tsis tau kov. Txhawm rau kom nkag siab txog lub zog hluav taws xob uas tuaj yeem ua haujlwm ntawm qhov deb, lub tswv yim ntawm lub zog hluav taws xob tshwm sim. Lub tswv yim ntawm lub zog hluav taws xob tau tsim los ntawm tus kws tshawb fawb Askiv Michael Faraday (1791-1867).
Kev txhais ntawm lub zog hluav taws xob (E)
Xav tias ib lub iav thaum chiv thawj tsis muaj hluav taws xob. Tom qab raug txhuam nrog daim ntaub, tus pas iav yuav raug them hluav taws xob. Thaum tus pas iav raug them hluav taws xob, tib lub sijhawm, lub teb hluav taws xob tshwm sim nyob ib puag ncig lub iav. Yog tias lub iav tig tsis muaj hluav taws xob, tib lub sijhawm lub teb hluav taws xob ploj mus. Yog li, qhov muaj E tsis tuaj yeem sib cais los ntawm qhov muaj hluav taws xob. E tsis yog ib hom khoom zoo li huab cua thiab tsis yog ib hom nthwv dej, zoo li nthwv dej electromagnetic. E yog ib yam dab tsi tshwm sim los ntawm hluav taws xob thiab cuam tshuam rau qhov chaw nyob ib puag ncig hluav taws xob, qhov twg lwm cov hluav taws xob tsuas yog hnov qhov cuam tshuam ntawm E.
Yuav kom paub tseeb tias puas muaj E nyob hauv ib chav, xav tias muaj ib qho nqi sim nyob rau hauv qhov chaw ntawd. Qhov nqi sim yog qhov them tsawg kawg nkaus (Q) yog li ntawd qhov nqi tsim hluav taws xob me me, yog li nws tuaj yeem tsis quav ntsej. Txawm li cas los xij, qhov nqi sim tuaj yeem hnov qhov cuam tshuam ntawm lub zog hluav taws xob uas tsim los ntawm lwm cov nqi hluav taws xob. Qhov nqi sim tsuas yog nthuav tawm los tshawb xyuas seb puas muaj E. Yog tias muaj E nyob rau hauv qhov chaw,
Lub zog hluav taws xob yuav tsum muaj zog, thiab yog tias tsis muaj E, lub zog hluav taws xob yuav tsum tsis muaj zog.
Saib daim duab ntawm sab.
Hauv daim duab 1, tus nqi +q 1 thiab tus nqi +q 2 tsim E hauv qhov chaw ib puag ncig. Thaum tus nqi sim +q o raug tso rau ntawm ib qho chaw hauv qhov chaw, tus nqi sim +q o ntsib lub zog hluav taws xob. F 1 yog lub zog hluav taws xob uas tus nqi +q 1 tso rau ntawm tus nqi sim +q o , thiab F 2 yog lub zog hluav taws xob uas tus nqi +q 2 tso rau ntawm tus nqi sim +q o . Hauv Daim Duab 2, thaum tus nqi sim raug tshem tawm, E tseem nyob thiab tsis ploj ntawm qhov ntawd. E 1 yog lub teb hluav taws xob tsim los ntawm tus nqi hluav taws xob +q 1 , thiab E 2 yog E tsim los ntawm tus nqi hluav taws xob +q 2.
Qhov loj ntawm lub zog hluav taws xob
Tus E yog ib qho vector ntau, qhov twg lub teb hluav taws xob muaj qhov loj thiab kev coj. Qhov loj ntawm E feem ntau yog hu ua lub zog E. Lub zog ntawm E ntawm ib qho taw tes yog txhais tias yog lub zog ntawm hluav taws xob uas siv los ntawm lub zog hluav taws xob ntawm qhov them kuaj zoo uas muab tso rau ntawm qhov ntawd, faib los ntawm qhov loj ntawm qhov them kuaj.
E = lub zog hluav taws xob
F = lub zog hluav taws xob
q = qhov them sim
Lub chav ntawm lub zog hluav taws xob yog Newton, thiab lub chav ntawm lub zog hluav taws xob yog Coulomb yog li ntawd lub chav ntawm E yog Newton / Coulomb, luv ua N/C.
Kev taw qhia ntawm lub zog hluav taws xob
Hauv Daim Duab 1a, lub zog hluav taws xob zoo (+Q) siv lub zog hluav taws xob rau ntawm lub zog kuaj zoo (+q), qhov twg qhov kev taw qhia ntawm lub zog hluav taws xob (F) nyob deb ntawm lub zog ntawm +Q.
Hauv Daim Duab 1b, thaum lub nqi kuaj raug tshem tawm, ntawm qhov no muaj lub teb hluav taws xob (E) uas nws qhov kev taw qhia nyob deb ntawm lub nqi hluav taws xob Q.
Hauv Daim Duab 2a, lub zog hluav taws xob tsis zoo (-Q) siv lub zog hluav taws xob hauv lub zog kuaj zoo (+ q), qhov twg qhov kev taw qhia ntawm lub zog hluav taws xob (F) mus txog qhov them -Q.
Hauv Daim Duab 2b, thaum lub nqi kuaj raug tshem tawm, ntawm qhov no muaj lub teb hluav taws xob (E) uas nws qhov kev taw qhia ze rau lub nqi hluav taws xob -Q.
Raws li daim duab thiab cov lus piav qhia saum toj no, nws tuaj yeem xaus lus tias qhov kev taw qhia ntawm lub teb hluav taws xob yog deb ntawm qhov hluav taws xob zoo thiab mus txog qhov hluav taws xob tsis zoo.
Cov kab hluav taws xob
Tus E yog tsim los ntawm lub zog hluav taws xob thiab cuam tshuam rau qhov chaw nyob ib puag ncig lub zog hluav taws xob, qhov twg qhov cuam tshuam ntawm E tsuas yog hnov los ntawm lwm cov zog hluav taws xob. Thaum lwm lub zog hluav taws xob nyob hauv E uas tsim los ntawm lub zog hluav taws xob, lwm lub zog hluav taws xob hnov qhov cuam tshuam ntawm lub zog hluav taws xob.
Kev nkag siab txog lub zog hluav taws xob saum toj no, raws li tau piav qhia hauv tsab xov xwm txog E, tuaj yeem paub nrog lub siab tab sis tsuas yog xav txog hauv lub siab xwb. Txhawm rau pom E, cov kab hluav taws xob tau nthuav tawm. Cov kab hluav taws xob yog cov kab kos ib puag ncig lub zog hluav taws xob los qhia txog qhov muaj nyob ntawm lub zog hluav taws xob. Vim tias nws lub hom phiaj los qhia qhov muaj nyob ntawm E, muaj kev sib txuas ntawm cov kab no nrog E. Hauv lwm lo lus, qhov loj thiab kev coj ntawm E tuaj yeem piav qhia los ntawm kev kos cov kab hluav taws xob.
Cov hauv qab no yog kev sib raug zoo ntawm kev taw qhia thiab lub zog hluav taws xob nrog cov kab hluav taws xob:
Ua ntej, qhov kev taw qhia ntawm E txav deb ntawm qhov them zoo thiab mus txog qhov them tsis zoo. Yog li, qhov kev taw qhia ntawm cov kab hluav taws xob kuj nyob deb ntawm qhov them zoo thiab mus txog qhov them tsis zoo.
Yog tias tus nqi zoo nyob ib sab ntawm tus nqi tsis zoo, cov kab hluav taws xob raug rub tawm ntawm tus nqi zoo mus rau tus nqi tsis zoo. Ntawm qhov tod tes, yog tias tus nqi zoo nyob ib sab ntawm tus nqi zoo, cov kab hluav taws xob raug rub tawm ntawm txhua tus nqi zoo thiab deb ntawm ib leeg.
Qhov thib ob, lub zog ntawm lub teb hluav taws xob yog sawv cev los ntawm qhov deb ntawm cov kab hluav taws xob. Qhov ze dua qhov deb ntawm cov kab ntawm lub teb hluav taws xob, qhov siab dua lub zog ntawm lub teb hluav taws xob thiab qhov deb dua qhov deb ntawm cov kab ntawm lub teb hluav taws xob, qhov me dua lub zog ntawm lub teb hluav taws xob.
Vim li cas, qhov ze dua qhov deb ntawm cov kab, qhov siab dua lub zog hluav taws xob? Txhawm rau nkag siab qhov no, saib cov lus piav qhia hauv qab no. Xav tias muaj tus nqi zoo nyob hauv nruab nrab ntawm lub voj voog thiab cov kab hluav taws xob kis mus rau ntau qhov kev taw qhia los ntawm qhov chaw ntawm lub voj voog. Yog tias tus lej ntawm cov kab hluav taws xob yog N thiab thaj chaw ntawm lub voj voog yog 4πr2 , ces tus lej ntawm cov kab ib cheeb tsam lossis qhov ceev ntawm kab yog N / 4πr2 . Raws li cov mis no, rau tib N, yog tias r me dua, qhov deb ntawm cov kab ze dua thiab yog tias r tseem ceeb dua qhov deb ntawm cov kab yuav deb dua.
Cov mis ntawm lub zog hluav taws xob E = kq / r2 kuj qhia tau hais tias lub zog hluav taws xob yog inversely proportional rau lub square ntawm qhov deb. Yog tias r me dua, ces lub zog hluav taws xob yuav pom tseeb dua, thiab yog tias r pom tseeb dua, ces lub zog hluav taws xob yuav me dua.
Raws li kev tshuaj xyuas saum toj no, nws tuaj yeem xaus lus tias yog tias r me dua (nyob ze rau lub zog hluav taws xob) lub zog hluav taws xob loj dua thiab qhov deb ntawm cov kab kuj nyob ze dua. Ntawm qhov tod tes, yog tias r pom tseeb dua (nyob deb ntawm lub zog hluav taws xob), lub zog hluav taws xob me dua thiab qhov deb ntawm cov kab kuj nyob deb dua.
Qhov thib peb, tus naj npawb ntawm cov kab E yog sib npaug rau lub zog hluav taws xob. Cov kab hluav taws xob ntau dua, lub zog hluav taws xob siab dua. Cov kab hluav taws xob tsawg dua, lub zog hluav taws xob me dua.
