Acceleration vs Retardation
Lub tswv yim ntawm kev nrawm yog qhov tseem ceeb thaum nws los kawm txog kev txav lub cev. Acceleration yog hais txog tus nqi ntawm kev hloov ceev ntawm lub cev txav. Yog hais tias lub cev txav ntawm qhov nrawm nrawm, tsis muaj qhov hloov pauv thiab yog li nws tsis muaj kev nrawm. Koj tuaj yeem nkag siab lub tswv yim nrog lub tsheb txav. Yog tias koj tsav tsheb thiab txav ntawm qhov ceev ntawm 50mph, koj tsis nrawm, tab sis lub sijhawm koj pib nias lub accelerator thiab nias nws ntxiv ntawm tus nqi tas li, lub tsheb nrawm dua li nws qhov nrawm nce ntawm tus nqi tas li. Qhov no yog hu ua acceleration. Muaj lwm lub tswv yim txuas nrog acceleration, thiab hu ua retardation uas tib neeg tseem tsis meej pem nrog. Kab lus no yuav piav qhia meej txog qhov sib txawv ntawm kev nrawm thiab qeeb kom tshem tawm cov kev xav tsis thoob hauv lub siab ntawm cov neeg nyeem.
Yog tias koj saib kev sib tw caij tsheb kauj vab, koj feem ntau pom tus neeg caij tsheb kauj vab hla dhau lwm tus neeg caij tsheb kauj vab. Qhov no tshwm sim vim tias tus neeg caij tsheb kauj vab nrawm nrawm nrawm nrawm dua li qhov qeeb qeeb. Tab sis muaj ntau tshaj rau nws tshaj catches koj ob lub qhov muag. Yog tias tus neeg caij tsheb qeeb qeeb txav ntawm qhov nrawm, nws tsis muaj kev nrawm. Tab sis nws pom tseeb tias tus tuaj tom qab tau nrawm dua, nws tau txais kev hloov nrawm uas pab nws mus dhau qhov qeeb qeeb. Qhov kev hloov pauv ntawm qhov nrawm lossis hloov nrawm ntawm ib chav tsev ntawm lub sijhawm hu ua acceleration thiab tau piav qhia los ntawm Newton txoj cai ntawm kev txav.
Yog tias koj yog qhov nrawm nrawm thiab v yog qhov kawg tshaj tawm ntawm tus neeg caij tsheb kauj vab, acceleration yog muab los ntawm kab zauv hauv qab no
V=U + at
Or, a=(V – U)/t
Txawm li cas los xij, muaj qee zaus thaum lub cev txav ceev yuav qeeb qeeb xws li thaum tus neeg tsav tsheb siv nres ntawm lub teeb tsheb lossis thaum lub tsheb ciav hlau ceev nrawm nres qeeb ntawm qhov chaw nres tsheb. Ntawm no kuj muaj qhov hloov pauv ntawm qhov nrawm tab sis qhov sib piv rau acceleration, qhov tshaj tawm yog txo. Cov xwm txheej no yog hu ua mob retardation (los yog deceleration). Cia peb pom nws nrog ib qho piv txwv. Thaum ib tug me nyuam tub pov ib lub pob hauv huab cua, lub pob muaj qee qhov pib tshaj tawm uas maj mam txo kom txog thaum lub pob nce mus txog qhov siab tshaj plaws hauv huab cua. Qhov no txhais tau hais tias qhov no yog qhov teeb meem ntawm retardation. Ntawm qhov tod tes, thaum lub pob pib nws txoj kev nqes mus, nws muaj qhov pib tshaj tawm ntawm xoom tab sis nws nce maj mam hauv qab lub ntiajteb txawj nqus thiab yog qhov siab tshaj plaws ua ntej nws tsoo hauv av. Nov yog rooj plaub ntawm acceleration.
