Kinematics yog dab tsi? Qhov no yog subfield ntawm mechanics uas kawm txog lej thiab geometric txoj kev piav qhia txog kev txav ntawm cov khoom zoo. Lawv poob rau hauv ob peb pawg. Lub ntsiab lus ntawm tsab xov xwm niaj hnub no yuav yog yam uas muaj feem cuam tshuam nrog lub tswvyim ntawm "point kinematics". Peb yuav hais txog ntau lub ntsiab lus, tab sis peb yuav pib nrog cov ntsiab lus tseem ceeb tshaj plaws thiab cov lus piav qhia ntawm lawv daim ntawv thov hauv cheeb tsam no.
Yuav ua li cas cov khoom raug txiav txim siab?
Yog tias kinematics yog ib ceg ntawm physics uas kawm yuav ua li cas piav qhia txog kev txav ntawm lub cev hauv qhov chaw sib txawv, ces koj yuav tsum ua haujlwm nrog lub cev lawv tus kheej, txoj cai? Txhawm rau kom nkag siab sai sai rau qhov muaj feem cuam tshuam, koj tuaj yeem nrhiav cov lus qhia multimedia uas tsim los rau cov tub ntxhais kawm. Kinematics feem ntau yooj yim to taub, yog tias koj nkag siab nws cov hauv paus. Thaum koj paub nrog lawv, koj yuav pom tias nyob rau hauv txoj kev xav muaj cov ntaub ntawv hais tias ceg ntawm physics no kawm txog cov cai ntawm kev txav ntawm cov khoom siv.cov ntsiab lus. Daim ntawv ceeb toom yuav ua li cas lub ntsiab txhais ntawm cov khoom yog generalized. Ntawm qhov tod tes, cov ntsiab lus ntawm cov khoom siv tsis yog tib yam khoom suav nrog kinematics. Cov ceg ntawm physics no kawm txog cov hauv paus ntsiab lus ntawm kev txav ntawm ob lub cev nruj thiab cov dej zoo tagnrho. Feem ntau tag nrho peb lub ntsiab lus no tau muab tso ua ke rau hauv ib qho, tsuas yog hais tias "cov khoom zoo tshaj plaws". Qhov zoo tshaj plaws nyob rau hauv cov ntaub ntawv no yog xav tau rau lub conventions ntawm xam thiab tawm mus los ntawm systematic yuam kev. Yog tias koj saib ntawm lub ntsiab lus ntawm cov khoom siv, koj yuav pom tias cov hauv qab no tau sau txog nws: qhov no yog lub cev uas nws qhov ntev tuaj yeem tsis quav ntsej hauv qhov xwm txheej sib xws. Qhov no tuaj yeem nkag siab tau raws li hauv qab no: piv rau qhov kev ncua deb, qhov ntev ntawm cov khoom yog negligible.
siv los piav dab tsi?
Raws li tau hais ua ntej, kinematics yog ib ntu ntawm cov tshuab uas kawm yuav ua li cas piav qhia qhov kev txav ntawm qhov taw tes. Tab sis yog tias qhov no yog li ntawd, nws puas txhais tau tias qee lub ntsiab lus thiab cov ntsiab lus tseem ceeb, zoo li cov axiomatic, xav tau los ua cov haujlwm zoo li no? Yog lawm. Thiab nyob rau hauv peb cov ntaub ntawv, lawv yog. Ua ntej, hauv kinematics nws yog ib txoj cai los daws cov teeb meem yam tsis tau saib rov qab ntawm lub zog ua haujlwm ntawm cov khoom siv. Peb txhua tus paub zoo tias lub cev yuav nrawm lossis qeeb yog tias muaj qee yam quab yuam ua rau nws. Thiab kinematics yog ntu ntu uas tso cai rau koj ua haujlwm nrog kev nrawm. Txawm li cas los xij, qhov xwm txheej ntawm cov rog tshwm sim tsis suav nrog ntawm no. Txhawm rau piav qhia txog kev txav mus los, cov txheej txheem ntawm kev txheeb xyuas lej, kab thiab spatial geometry yog siv, thiabkuj algebra. Coordinate grids thiab cov coordinates lawv tus kheej kuj ua lub luag hauj lwm. Tab sis peb yuav tham txog qhov no me ntsis tom qab.
History of Creation
Thawj cov haujlwm ntawm kinematics tau suav sau los ntawm tus kws tshawb fawb zoo Aristotle. Nws yog nws uas tsim ib co ntawm cov hauv paus ntsiab lus ntawm kev lag luam no. Thiab txawm hais tias nws cov haujlwm thiab cov lus xaus muaj ntau qhov kev xav tsis raug thiab kev xav, nws cov haujlwm tseem muaj txiaj ntsig zoo rau niaj hnub physics. Aristotle cov haujlwm tom qab tau kawm los ntawm Galileo Galilei. Nws tau ua qhov kev sim nto moo nrog Leaning Ntauwd ntawm Pisa, thaum nws tshawb xyuas cov cai ntawm cov txheej txheem ntawm kev poob dawb ntawm lub cev. Tom qab kawm txhua yam sab hauv thiab sab nraud, Galileo raug Aristotle qhov kev xav thiab cov lus xaus rau kev thuam hnyav. Piv txwv li, yog tias yav tas los sau tias lub zog yog qhov ua rau kev txav, Galileo tau ua pov thawj tias lub zog yog qhov ua rau kom nrawm, tab sis tsis yog lub cev yuav tuaj tos thiab pib txav thiab txav mus. Raws li Aristotle, lub cev tuaj yeem tau txais kev nrawm tsuas yog thaum raug rau qee lub zog. Tab sis peb paub tias qhov kev xav no yog qhov yuam kev, vim tias muaj kev hloov pauv tsis sib xws. Qhov no yog ib zaug ua pov thawj los ntawm cov qauv ntawm kinematics. Thiab peb mam li mus rau lo lus nug tom ntej.
Kinematics. Physics. Cov ntsiab lus tseem ceeb
Muaj ntau lub hauv paus ntsiab lus thiab cov ntsiab lus hauv nqe lus no. Cia peb pib nrog lub ntsiab.
Mechanical zog
Tias, los ntawm lub tsev kawm ntawv lub rooj ntev zaum peb tab tom sim nteg lub tswv yim ntawm dab tsi tuaj yeem suav hais tias yog kev txav mus los. Peb suav nrog nws txhua hnub, teev, txhua thib ob. Peb yuav xav txog txhua yam kev txav mus los ntawm cov txheej txheem uas tshwm sim hauv qhov chaw dhau sijhawm, uas yog, kev hloov pauv ntawm txoj haujlwm ntawm lub cev. Nyob rau tib lub sijhawm, kev sib raug zoo feem ntau siv rau cov txheej txheem, uas yog, lawv hais tias txoj hauj lwm ntawm, hais tias, thawj lub cev tau hloov mus rau qhov chaw ntawm qhov thib ob. Cia peb xav tias peb muaj ob lub tsheb ntawm txoj kab pib. Kev mus tom ntej ntawm tus neeg teb xov tooj lossis lub teeb ci - thiab lub tsheb tawm mus. Thaum pib muaj twb hloov txoj hauj lwm lawm. Tsis tas li ntawd, koj tuaj yeem tham txog qhov no rau lub sijhawm ntev thiab tediously: hais txog tus neeg sib tw, hais txog kab pib, hais txog tus neeg saib xyuas. Tab sis tej zaum lub tswv yim yog qhov tseeb. Tib yam tuaj yeem hais txog ob tus neeg uas mus rau hauv ib qho kev coj lossis sib txawv. Txoj hauj lwm ntawm lawv txhua tus txheeb ze rau lwm qhov kev hloov pauv ntawm txhua lub sijhawm.
Reference system
Kinematics, physics - tag nrho cov kev tshawb fawb no siv cov ntsiab lus tseem ceeb xws li cov qauv siv. Qhov tseeb, nws ua lub luag haujlwm tseem ceeb heev thiab yog siv rau hauv cov teeb meem tshwm sim yuav luag txhua qhov chaw. Ob qhov tseem ceeb ntxiv tuaj yeem txuas nrog tus ncej ntawm kev siv.
Kev sib faib kab sib chaws thiab kev tswj hwm
Cov tom kawg tsis muaj dab tsi ntau tshaj li sau cov lej thiab ntawv. Siv qee qhov kev teeb tsa kev xav, peb tuaj yeem sau peb tus kheejib-dimensional lossis ob-dimensional coordinate grid, uas yuav tso cai rau peb los daws cov teeb meem yooj yim tshaj plaws ntawm kev hloov txoj haujlwm ntawm cov khoom taw tes rau lub sijhawm. Feem ntau, nyob rau hauv kev xyaum, ib tug ob-dimensional daim phiaj yog siv nrog lub axes X ("x") thiab Y ("y"). Hauv qhov chaw peb-dimensional, nws ntxiv Z axis ("z"), thiab hauv ib-seem qhov chaw, tsuas yog X xwb. Artillerymen thiab scouts feem ntau ua haujlwm nrog kev tswj xyuas. Thiab thawj zaug peb ntsib lawv hauv tsev kawm theem qis, thaum peb pib kos ntu ntawm qhov ntev. Tom qab tag nrho, kev kawm tiav tsis muaj dab tsi ntau tshaj li kev siv cov kev tswj xyuas los qhia qhov pib thiab xaus.
Kinematics Qib 10. Quantities
Cov khoom tseem ceeb siv los daws cov teeb meem ntawm kinematics ntawm cov khoom taw tes yog qhov deb, sijhawm, nrawm thiab nrawm. Cia peb tham txog ob qho kawg hauv kev nthuav dav ntxiv. Ob qho ntawm cov khoom no yog vector. Nyob rau hauv lwm yam lus, lawv tsis tau tsuas yog ib tug lej qhia, tab sis kuj muaj ib tug tej yam predetermined kev taw qhia. Lub zog ntawm lub cev yuav tshwm sim nyob rau hauv cov kev taw qhia nyob rau hauv uas lub velocity vector yog qhia. Nyob rau tib lub sij hawm, ib tug yuav tsum tsis txhob hnov qab txog lub acceleration vector yog hais tias peb muaj ib tug teeb meem ntawm uneven txav. Acceleration tuaj yeem coj mus rau tib qho kev taw qhia lossis nyob rau hauv qhov sib txawv. Yog tias lawv tau sib koom ua ke, ces lub cev yuav pib txav nrawm dua thiab nrawm dua. Yog tias lawv tawm tsam, ces qhov khoom yuav qeeb kom txog thaum nws nres. Tom qab ntawd, nyob rau hauv lub xub ntiag ntawm acceleration, lub cev yuav kis tau tus opposite ceev, uas yog, nws yuav tsiv mus nyob rau opposite kev taw qhia. Tag nrho cov no nyob rau hauv kev xyaum yog heev, heev kom meej meej qhia los ntawm kinematics. Qib 10 ntawd xwblub sijhawm uas seem ntawm physics tau nthuav tawm txaus.
Formula
Kinematics cov qauv yog qhov yooj yim heev rau kev tso tawm thiab rau kev nco. Piv txwv li, tus qauv rau qhov kev ncua deb ntawm ib yam khoom nyob rau hauv ib lub sij hawm muab raws li nram no: S=VoT + aT^2/2. Raws li peb pom, ntawm sab laug peb tsuas muaj qhov sib nrug deb. Ntawm sab xis, koj tuaj yeem pom qhov pib nrawm, lub sijhawm thiab acceleration. Cov kos npe ntxiv tsuas yog muaj cai xwb, txij li kev nrawm tuaj yeem coj tus nqi tsis zoo thaum lub sijhawm cov khoom deceleration. Nyob rau hauv dav dav, lub kinematics ntawm tsab ntawv tsa suab implies lub hav zoov ntawm ib hom kev ceev, peb pheej hais tias "thawj", "kawg", "instantaneous". Instantaneous ceev tshwm nyob rau ntawm ib qho chaw nyob rau hauv lub sij hawm. Tab sis tom qab tag nrho, yog tias koj xav li ntawd, ces qhov kawg lossis cov khoom pib tsis muaj dab tsi tab sis nws cov kev tshwm sim tshwj xeeb, txoj cai? Lub ntsiab lus "Kinematics" yog qhov nyiam ntawm cov menyuam kawm ntawv, vim nws yooj yim thiab nthuav.
Piv txwv cov teeb meem
Nyob hauv qhov yooj yim tshaj plaws kinematics, muaj tag nrho cov haujlwm sib txawv heev. Tag nrho cov ntawm lawv yog kev cob cog rua nyob rau hauv ib txoj kev los yog lwm yam nrog lub zog ntawm ib tug khoom point. Piv txwv li, hauv qee qhov nws yuav tsum tau txiav txim siab qhov kev ncua deb ntawm lub cev mus rau hauv ib lub sijhawm. Nyob rau hauv rooj plaub no, tsis xws li pib tshaj tawm thiab acceleration yuav paub. Los yog tej zaum tus menyuam kawm ntawv yuav tau txais ib txoj hauj lwm, uas yuav cia li muaj nyob rau hauv qhov yuav tsum tau qhia thiab xam lub acceleration ntawm lub cev. Cia peb ua piv txwv. Lub tsheb pib los ntawm qhov chaw zoo li qub. Qhov kev ncua deb nws yuav muaj sij hawm los npog hauv 5 vib nas this yog tias nws acceleration yog peb meters,muab faib los ntawm ib tug thib ob squared?
Yuav daws qhov teeb meem no, peb xav tau tus qauv S=VoT + at^2/2. Peb tsuas yog hloov cov ntaub ntawv muaj nyob rau hauv nws. Nws yog acceleration thiab lub sij hawm. Nco ntsoov tias lo lus Vot yuav mus rau xoom, txij li thaum pib tshaj tawm yog xoom. Yog li, peb tau txais cov lus teb tus lej ntawm 75 meters. Qhov ntawd yog nws, teeb meem daws tau.
Results
Yog li, peb xam pom cov ntsiab lus tseem ceeb thiab cov ntsiab lus, muab piv txwv ntawm cov qauv thiab tham txog keeb kwm ntawm kev tsim ntawm ntu ntu no. Kinematics, lub tswv yim uas tau qhia nyob rau qib xya hauv physics cov lus qhia, txuas ntxiv txhim kho tas li nyob rau hauv lub moj khaum ntawm kev sib raug zoo (tsis yog classical).
