Li cas rau cov wavelength

Lub cev vibrating nyob rau hauv ib tug elastic nruab nrab, tsim ib tug ntxaug uas yog kis los ntawm ib tug taw tes rau lwm tus, thiab yog hu ua ib tug yoj. Qhov no tshwm sim nyob rau hauv ib tug tej yam nqi, uas yog xam ceev ntawm nws kis. Uas yog ib tug nqi uas characterizes qhov kev ncua deb mus ncig los ntawm tej yam taw tes rau ntawm lub yoj ib chav tsev ntev ntawm lub sij hawm.

Cia nthwv dej tsiv raws ib axis (e.g., kab rov tav). Nws zoo yog pheej rov qab ua nyob rau hauv lub qhov chaw thaum lub sij hawm, t. E. Lub yoj profile tsiv raws hais tawm axis nrog ib tug tshaj tawm muaj ib tug tsis tu ncua nqi. Thaum lub sij hawm coj mus rau lub sij hawm ntawm oscillation, nws ntug moog ib tug deb, raug xa mus rau raws li ib tug wavelength.

Yog li ntawd, lub wavelength - tib yam deb, uas "sau" ntawm nws cov pem hauv ntej thaum lub sij hawm lub sij hawm luv sib npaug zos rau lub sij hawm ntawm oscillation. Yuav kom pom tau nthwv dej nyob rau hauv daim ntawv nyob rau hauv uas nws yog feem ntau xwm li nyob rau hauv cov nuj nqis. Peb nco ntsoov qhov zoo ntawm, piv txwv li, lub hiav txwv tsis. Cua drives lawv raws hiav txwv, thiab txhua yoj muaj ib tug Crest (high point) thiab tus nqi qis tshaj point (yam tsawg kawg), thiab cov neeg thiab lwm tus neeg tas li tsiv thiab hloov txhua lwm yam. Cov ntsiab lus dag nyob rau hauv ib theem, - tus vertices ntawm ob uas nyob ib sab crests (Nco ntsoov ib tug assumption tias cov ridges muaj tib lub siab thiab cov lus tsa suab yog ntawm qhov ceev), los yog ob tug qis tshaj cov ntsiab lus ntawm ib sab tsis. Wavelength - yog precisely qhov kev ncua deb ntawm tej ntsiab lus (ob uas nyob ib sab crests).

Nyob rau hauv daim ntawv ntawm cov tsis tau propagate tag nrho cov hom ntawm lub zog - thaum tshav kub kub, lub teeb, suab. Lawv tag nrho cov muaj ntau lengths. Piv txwv li, dhau los ntawm lub ntuj kaaj quas lug, lub suab tsis me ntsis hloov cua siab. Pawg sib haum mus rau lub maxima ntawm lub siab tshaj plaws siab ntawm lub suab tsis. Vim nws cov qauv, cov tib neeg pob ntseg picks cov kev hloov no nyob rau hauv siab thiab xa Pib ntsais koj teeb mus rau lub hlwb. Yog li peb hnov lub suab.

suab yoj ntev txiav txim nws lub zog. Yuav kom nrhiav tau nws tsim nyog yoj ceev (ntsuas nyob rau hauv m / sec) muab faib los ntawm cov zaus nyob rau hauv Hz. Piv txwv li: lub zaus 688 Hz suab yoj tsiv ntawm ib tus nqi ntawm 344 m / sec. Cov wavelength yuav ces yuav sib npaug zos rau 344: 688 = 0.5m yog lub npe hu hais tias tus yoj tshaj tawm nyob rau hauv tib cheeb tsam tsis hloov, yog li ntawd, nws ntev yuav yog nyob ntawm seb zaus .. Tsawg zaus suab tsis muaj ib tug wavelength ntev tshaj li siab.

Ib qho piv txwv ntawm lwm variation ntawm lub electromagnetic tawg yuav pab raws li ib lub teeb yoj. Lub teeb - ib feem ntawm lub electromagnetic spectrum, tus pom mus rau lub qhov muag. Cov wavelength ntawm lub teeb uas tib neeg qhov muag yuav pom, nyob rau hauv ntau ntawm 400 rau 700 nm (nanometers). Nyob rau ntawm ob sab ntawm lub pom ntau yam ntawm lub spectrum pw hauv lub teb, tsis txhob muab peb lub qhov muag.

Ultraviolet tsis muaj ib tug ntev tsawg tshaj li qhov ntev ntawm lub pom spectrum. Thaum tus tib neeg qhov muag pom tsis tau lawv, tab sis, cuaj kaum, lawv muaj peev xwm ua rau zoo kawg raug mob rau peb pom.

Cov wavelength ntawm infrared tawg ntau dua qhov nyiaj pab ntau tshaj ntev hais tias peb yuav pom. Cov tsis muaj ntes tau los ntawm tshwj xeeb cov khoom thiab siv, piv txwv li, ib tug pom thaum tsaus ntuj cov koob yees duab.

Cov rays muaj rau peb lub zeem muag, qhov tsawg tshaj plaws ntev ntawm lub beam muaj ib tug violet xim, lub biggest - liab. Nruab nrab ntawm lawv cov lus dag tag nrho cov ntau yam ntawm muaj saib (nco ntsoov tus zaj sawv!)

Yuav ua li cas peb tau perceive xim? Rays ntawm lub teeb muaj ib tug predetermined ntev, poob rau hauv retina, muaj ib lub teeb-sensitive receptors. Cov receptors kis Pib ntsais koj teeb ncaj qha mus rau hauv peb lub hlwb, qhov chaw uas lub nov ntawm nqaij tawv ntawm ib tug tej yam xim yog tsim. Yuav ua li cas yog cov xim peb pom - nws nyob ntawm lub wavelength ntawm qhov teeb meem rays, thiab qhov kev ci ntawm cov xim nov ntawm nqaij tawv yog txiav txim los ntawm cov kev siv ntawm hluav taws xob.

Tag nrho cov khoom nyob ib ncig ntawm peb muaj peev xwm muaj kev cuam tshuam, kis los yog nqus teeb meem lub teeb (tag nrho los yog). Piv txwv li, nplooj ntsuab txhais tau tias tag nrho cov ntau yam ntawm lub thaws rov los rays yog mas ntsuab nyob rau hauv cov xim, tus so yog absorbed. Pob tshab khoom muaj ib tug ib txwm mus ncua cov emission ntawm ib tug tej yam ntev uas yog siv, piv txwv li, nyob rau hauv cov kev yees duab (siv yees duab cov ntxaij lim dej).

Yog li, cov xim ntawm ib tug kwv qhia rau peb muaj peev xwm muaj kev cuam tshuam lub vuag ntawm ib tug tej yam yog ib feem ntawm lub spectrum. Khoom uas muaj kev cuam tshuam rau tag nrho lub spectrum, peb pom dawb, absorbing tag nrho cov rays - dub.