siab vs qhov tob
Qhov siab yog qhov ntsuas ntawm qhov ntsug ntawm qhov khoom. Qhov tob kuj yog qhov ntsuas ntawm qhov ntsug qhov loj ntawm ib qho khoom. Ob lo lus no yuav zoo li sawv cev tib yam. Cov ntsiab lus no feem ntau intuitive, thiab peb feem ntau overlook lub ntsiab txhais ntawm cov ntsiab lus. Tab sis cov ntsiab lus no tau raug txhais kom raug thiab muaj cov ntsiab lus sib txawv hauv cov kev tshawb fawb zoo xws li physics, engineering thiab lej. Hauv tsab xov xwm no, peb yuav tham txog qhov siab thiab qhov tob yog dab tsi, cov ntsiab lus ntawm qhov siab thiab qhov tob, lawv qhov sib xws thiab thaum kawg qhov sib txawv ntawm qhov siab thiab qhov tob.
siab
Qhov siab yog lub cev kom muaj nuj nqis nrog qhov ntev ntawm qhov ntev. Tus qauv ntsuas ntsuas qhov siab yog lub 'meter'. Lub sij hawm qhov siab tuaj yeem siv rau hauv kev siv sib txawv. Qhov siab ntawm ib lub tsev lossis ib tus neeg txhais tau tias "siab" qhov khoom yog li cas. Qhov no yog qhov muaj tseeb. Qhov siab ntawm ib yam khoom xws li lub dav hlau txhais tau hais tias qhov khoom siab npaum li cas nrog rau qhov nruab nrab hiav txwv theem. Qhov no tseem hu ua qhov siab. Qhov siab ntawm ib lub dav hlau nrog rau lwm yam khoom yog qhov txheeb ze. Yog tias daim ntawv lej ntawm qhov siab yog coj los ua vector, qhov kev taw qhia ntawm nws yuav yog qhov zoo ntsug. Nyob rau hauv lub Cartesian coordinate system, qhov siab yog ntsuas nyob rau hauv qhov zoo y kev taw qhia. Qhov siab yog lub tswv yim intuitive, uas tau ntsib hauv lub neej txhua hnub.
Ntxhais
Qhov tob yog lub cev kom muaj nuj nqis, uas kuj muaj qhov ntev ntawm qhov ntev. Nws muaj tib tus qauv ntsuas ntsuas raws li qhov siab uas yog meters. Lub sij hawm qhov tob kuj tseem siv tau rau ntau daim ntawv thov. Qhov tob ntawm lub qhov dej los yog lub qhov txhais tau hais tias qhov tob npaum li cas yog qhov khoom nws tus kheej. Nws yog ib yam khoom ntawm qhov khoom. Nws kuj tseem siv tau los qhia tias qhov khoom sib sib zog nqus npaum li cas nrog rau qee qhov chaw hauv qhov chaw. Piv txwv li, yog hais tias lub submarine yog ib puas meters hauv qab no, nws qhia tau hais tias lub submarine yog muab tso rau 100 meters hauv qab no dej. Qhov tob yog ntsuas nyob rau hauv ib tug downward kev taw qhia. Yog hais tias qhov tob yog qhia nyob rau hauv ib daim ntawv vector, nws yuav coj cov kev taw qhia ntawm downward. Yog hais tias qhov tob yog qhia nyob rau hauv lub Cartesian coordinate system, nws yuav coj cov kev taw qhia ntawm qhov tsis zoo y-axis. Qhov tob kuj yog ib lub tswv yim intuitive. Rau ib yam khoom, qhov siab ntsuas los ntawm lub hauv qab ntawm cov khoom yog sib npaug rau qhov tob ntsuas los ntawm sab saum toj ntawm cov khoom. Qhov tob ntawm ib yam khoom nrog rau qee yam khoom siv tuaj yeem hu ua qhov tob ntawm qhov khoom.
Qhov sib txawv ntawm qhov tob thiab qhov siab yog dab tsi?
• Qhov tob yog ib txwm ntsuas nyob rau hauv lub downward direction, whereas qhov siab yog ib txwm ntsuas nyob rau hauv upward direction.
• Qhov tob feem ntau yog siv rau hauv thaj chaw xws li nautical engineering, geology thiab hydrodynamics. Qhov siab feem ntau yog siv rau hauv thaj chaw xws li aviation, kev siv tub rog thiab kev tshawb nrhiav chaw.
