Daim duab lub cev pub dawb yog qhov sawv cev pom ntawm lub hom phiaj thiab txhua yam ntawm sab nraud ua rau nws, yog li kos ib qho koj yuav tsum muaj cov ntaub ntawv no xam
Lawv yog ib qho tseem ceeb heev rau kev ua haujlwm hauv engineering lossis kev daws teeb meem lub cev vim tias teeb duab lawv pab koj nkag siab tias muaj dab tsi tshwm sim. Daim duab dawb-lub cev tuaj yeem kos tau yooj yim heev, nrog cov duab plaub thiab cov xub, lossis koj tuaj yeem ua rau nws nyuaj dua. Qhov xav tau tsuas yog koj lossis lwm tus neeg saib nws yuav tsum muaj peev xwm nkag siab tias daim duab qhia dab tsi.
Daim duab lub cev dawb (FBD) yog tus sawv cev ntawm qee yam khoom uas qhia tag nrho cov zog sab nraud uas ua rau nws. FBDs muaj txiaj ntsig zoo hauv kev tsim teeb meem engineering thiab physics.
Cov kauj ruam
Ntu 1 ntawm 2: Tsim Tus Qauv FBD
Kauj Ruam 1. Txheeb xyuas lub cev/khoom koj xav ua FBD ntawm
Piv txwv: Ib tug txiv neej tab tom thawb lub thawv 10kg rau ntawm qhov chaw ntxhib, nrog rau qhov sib txhuam coefficient ntawm µ = 0.6, los ntawm kev siv lub zog 20N. Koj yuav xaiv peb lub cev los ua lub thawv
Kauj Ruam 2. Kos ib qho yooj yim sawv cev ntawm lub cev
Piv txwv: Ua ib lub xwmfab los sawv cev rau lub npov
Kauj Ruam 3. Xav seb lub zog twg ua rau lub cev
Piv txwv: Cov no yog (1) qhov hnyav ntawm qhov khoom, (2) kev thawb tus txiv neej, (3) qhov kev quab yuam ib txwm siv los ntawm hauv pem teb, thiab (4) kev sib txhuam vim yog hauv pem teb ntxhib
Kauj Ruam 4. Kos cov quab yuam ib tus los ntawm ib qho uas siv cov xub taw qhia rau qhov kev taw qhia ntawm lub zog
Ib txwm pib nrog qhov hnyav vim tias txhua yam khoom muaj qhov hnyav.
Piv txwv: (1) Rau qhov hnyav, kos tus xub taw qhia qis vim tias qhov hnyav yog qhov rub lub zog ntawm lub ntiaj teb kev nqus, uas ib txwm nqes mus
Kauj Ruam 5. Kos cov rog uas seem
Piv txwv: (2) Kos tus xub uas ua raws cov lus qhia ntawm lub zog thawb. (3) Kos tus xub taw tes rau siab rau qhov ib txwm muaj zog vim tias nws yuav tsum ib txwm nyob ib puag ncig rau hauv pem teb. (4) Kos tus xub uas tawm tsam qhov kev taw qhia ntawm lub thawv rau kev sib txhuam
Kauj Ruam 6. Sau koj lub zog kom raug thiab koj li FBD yooj yim ua tiav
Txawm li cas los xij, yog tias koj xav muab qhov loj ntawm cov rog, koj tuaj yeem txuas ntxiv mus rau cov theem hauv qab no.
Ntu 2 ntawm 2: Ntxiv Qhov Loj ntawm Cov Tub Rog
Kauj Ruam 1. Ntxiv cov ntaub ntawv hais txog qhov hnyav
Qhov hnyav ntawm qhov khoom sib npaug rau qhov hnyav ntawm qhov khoom*nrawm vim yog lub ntiajteb txawj nqus.
- Piv txwv: W = m*a. W = (10kg)*(9.81m/s^2) = 98.1N. Sau qhov no ib sab ntawm nws cov xub.
- Nco tseg: Lub zog raug ntsuas hauv Newtons lossis N.
Kauj Ruam 2. Ntxiv lub zog thawb
Qhov loj ntawm lub zog thawb thov los ntawm tus txiv neej tau muab ua 20N. Sau qhov no ib sab ntawm nws cov xub.
Kauj Ruam 3. Ntxiv qhov quab yuam ib txwm muaj
Qhov quab yuam ib txwm yog sib npaug ntawm qhov hnyav ntawm qhov hnyav uas ua rau perpendicularly rau hauv pem teb. Hauv qhov no, txhua qhov hnyav ua rau ib leeg rau hauv pem teb, yog li ntawd, N thiab W muaj qhov sib npaug sib npaug. Yog li, N = 98.1N. Sau qhov no ib sab ntawm nws cov xub.
Kauj Ruam 4. Ntxiv qhov txhuam txhuam
Lub zog sib txhuam yog muab los ntawm tus qauv: f = µ*N. Yog li, f = 0.6*(98.1N) = 58.86N. Sau qhov no ib sab ntawm nws cov xub.
