Kev Sib Tsoo Tsis Sib Haum
Txoj cai txuag lub zog kinetic tsis siv tau rau hauv kev sib tsoo tsis sib luag. Txoj cai txuag lub zog momentum siv tau rau hauv kev sib tsoo tsis sib luag yog tias tsis muaj lub zog sab nraud ua rau ob yam khoom sib tsoo. Hauv kev sib tsoo tsis sib luag, ob yam khoom lo ua ke lossis txuas rau ib leeg tom qab kev sib tsoo.
Piv txwv lo lus nug 1.
Ob yam khoom muaj tib lub cev hnyav, uas yog 1 kg. Yam khoom 1 txav mus rau ntawm ib lub dav hlau tiaj tiaj nrog qhov ceev ntawm 10 m/s thiab tsoo nrog yam khoom thib ob uas tsis txav. Tom qab kev sib tsoo, ob yam khoom lo ua ke. Qhov ceev ntawm ob yam khoom tom qab kev sib tsoo yog dab tsi?
Paub:
m 1 = 1 kg, m 2 = 1 kg, v 1 = 10 m/s, v 2 = 0
Xav tau : v'
Tshuaj:
m 1 v 1 + m 2 v 2 = (m 1 + m 2 ) v'
(1 kg)(10 m/s) + 0 = (1 kg + 1 kg) v'
10 kg m/s = (2 kg) v'
v' = 10 kg m/s : 2 kg = 5 m/s
Piv txwv lo lus nug 2.
Peb lub blocks txav mus rau 3 ms -1 sib tsoo lwm lub block thaum so.
Qhov kev sib tsoo tsis sib haum. Qhov kev txiav txim ntawm qhov ceev ntawm lub block tom qab kev sib tsoo, los ntawm qhov loj tshaj plaws mus rau qhov me tshaj plaws yog…
Tshuaj:
Daim Duab 1:
Lub zog kawg = lub zog pib
m 1 v 1 + m 2 v 2 = (m 1 + m 2 ) v
(4m)(3) + (m)(0) = (4m + m) v
12m + 0 = (5m) v
12m = 5m v
v = 12m / 5m = 12/5 = 2.4 m/s
Daim Duab 2:
Lub zog kawg = Lub zog pib
m 1 v 1 + m 2 v 2 = (m 1 + m 2 ) v
(m)(3) + (3m)(0) = (m + 3m) v
3m + 0 = (4m) v
3m = 4m v
v = 3m / 4m = 3/4 = 0.75 m/s
Daim Duab 3:
m 1 v 1 + m 2 v 2 = (m 1 + m 2 ) v
(m)(3) + (m)(0) = (m + m) v
3m + 0 = (2m) v
3m = 2m v
v = 3m / 2m = 3/2 = 1.5 m/s
Piv txwv lo lus nug 3.
Ob lub pob uas muaj qhov hnyav ntawm m 1 = 2 kg thiab m 2 = 1 kg tab tom txav mus rau sab nraud nrog qhov ceev ntawm v 1 = 2 ms -1 thiab v 2 = 4 ms -1 raws li pom hauv daim duab hauv qab no. Yog tias kev sib tsoo tsis sib luag, qhov ceev ntawm ob lub pob tom qab kev sib tsoo yog dab tsi?
Paub:
Qhov hnyav ntawm lub pob 1 (m1) = 2 kg
Qhov hnyav ntawm lub pob 2 (m 2 ) = 1 kg
Qhov ceev ntawm lub pob 1 ua ntej sib tsoo (v 1 ) = 2 m/s
Qhov ceev ntawm lub pob 2 ua ntej sib tsoo (v 2 ) = -4 m/s
Cov cim ntxiv thiab rho tawm qhia tias ob lub pob txav mus rau hauv cov lus qhia sib txawv.
Xav tau : Qhov ceev ntawm cov pob tom qab sib tsoo (v')
Tshuaj:
m 1 v 1 + m 2 v 2 = (m 1 + m 2 ) v'
(2)(2) + (1)(-4) = (2 + 1) v'
4 – 4 = (3) v'
0 = (3) v'
v' = 0
Piv txwv lo lus nug 4.
Ob yam khoom, A thiab B, nrog rau qhov hnyav ntawm txhua yam khoom, yog 1.5-kg los ze rau ib leeg nrog qhov ceev ntawm v A = 4 ms -1 thiab v B = 5 ms -1 . Yog tias qhov kev sib tsoo tsis sib luag, qhov ceev ntawm ob yam khoom yog dab tsi tom qab kev sib tsoo?
Paub:
Qhov hnyav ntawm yam khoom A (m A ) = 1.5 kg
Qhov hnyav ntawm yam khoom B (mB ) = 1.5 kg
Qhov ceev ntawm yam khoom A ua ntej sib tsoo (v A ) = 4 m/s (ntxiv rau lub cim, mus rau sab xis)
Qhov ceev ntawm yam khoom B ua ntej sib tsoo (v B ) = -5 m/s (tsis muaj cim, mus rau sab laug)
Xav Tau: Qhov ceev ntawm ob yam khoom tom qab sib tsoo
Tshuaj:
Kev txuag ntawm linear momentum:
m A v A + m B v B = (m A + m B ) v'
(1.5)(4)+(1.5)(-5) = (1.5+1.5)v'
6 – 7.5 = (3) v'
-1.5 = (3) v'
v' = -1.5 / 3
v' = -0.5 m/s
Lub cim rho tawm qhia tias ob qho khoom txav mus rau sab laug.
20 cov lus nug thiab lus teb txog kev sib tsoo tsis sib xws:
1. Lo lus nug: Dab tsi txhais tau tias kev sib tsoo tsis sib luag? Lus teb: Hauv kev sib tsoo tsis sib luag, lub zog kinetic tsis raug khaws cia, txawm hais tias momentum yog. Qee lub zog kinetic thawj zaug raug hloov mus ua lwm hom zog.
2. Lo lus nug: Kev sib tsoo uas tsis sib txuas zoo sib xws txawv li cas ntawm kev sib tsoo uas tsis sib txuas ib nrab? Lus teb: Hauv kev sib tsoo uas tsis sib txuas zoo sib xws, cov khoom lo ua ke tom qab kev sib tsoo. Hauv kev sib tsoo uas tsis sib txuas ib nrab, cov khoom sib cais, tab sis tseem muaj kev poob ntawm lub zog kinetic.
3. Lo lus nug: Dab tsi tseem khaws cia rau hauv txhua hom kev sib tsoo, suav nrog cov uas tsis ywj pheej? Lus teb: Lub zog yeej ib txwm khaws cia rau hauv txhua qhov kev sib tsoo, tsis hais lawv qhov ywj pheej.
4. Lo lus nug: Vim li cas lub zog kinetic tsis khaws cia rau hauv kev sib tsoo tsis sib luag? Lus teb: Qee lub zog kinetic raug hloov mus ua lwm hom zog, xws li lub zog muaj peev xwm, cua sov, lossis suab.
5. Lo lus nug: Yuav ua li cas ib tug neeg thiaj paub qhov kev sib tsoo tsis sib luag los ntawm kev saib xyuas qhov ceev ua ntej thiab tom qab kev sib tsoo? Lus teb: Tag nrho lub zog kinetic ua ntej kev sib tsoo yuav loj dua tag nrho lub zog kinetic tom qab kev sib tsoo.
6. Lo lus nug: Puas yog kev sib tsoo tsis sib xws tuaj yeem tshwm sim hauv ib qho xwb? Teb: Tsis yog, kev sib tsoo tsis sib xws tuaj yeem tshwm sim hauv ib, ob, lossis peb qhov ntev. Cov ntsiab cai tseem zoo ib yam, tsuas yog cov kev suav vector ua rau nyuaj dua.
7. Lo lus nug: Hauv cov ntsiab lus ntawm particle physics, qhov tshwm sim feem ntau ntawm kev sib tsoo tsis sib xws yog dab tsi? Lus teb: Hauv particle physics, kev sib tsoo tsis sib xws feem ntau ua rau muaj kev hloov pauv ntawm cov khoom sib tsoo mus rau hauv cov khoom sib txawv.
8. Lo lus nug: Koj yuav ua li cas thiaj paub qhov ntau ntawm lub zog poob hauv kev sib tsoo tsis sib xws? Lus teb: Los ntawm kev xam qhov sib txawv ntawm tag nrho lub zog kinetic pib thiab tag nrho lub zog kinetic kawg.
9. Lo lus nug: Vim li cas kev sib tsoo tsis sib haum tsis ua txhaum txoj cai ntawm kev txuag lub zog? Lus teb: Lub zog tseem raug txuag; nws tsuas yog hloov pauv los ntawm ib daim ntawv (kinetic) mus rau lwm daim ntawv (xws li cua sov lossis suab) es tsis txhob nyob ua lub zog kinetic xwb.
10. Lo lus nug: Feem ntau cov kev sib tsoo hauv ntiaj teb tiag tiag puas yog inelastic? Teb: Yog, feem ntau cov kev sib tsoo hauv ntiaj teb tiag tiag yog inelastic vim tias feem ntau muaj qee qhov kev hloov pauv ntawm lub zog kinetic mus rau lwm hom.
11. Lo lus nug: Hauv kev sib tsoo tsis sib luag, yog tias ob yam khoom lo ua ke, yuav hais li cas txog lawv qhov ceev ua ke? Lus teb: Lawv qhov ceev ua ke yog txiav txim siab los ntawm kev txuag lub zog. Ob yam khoom yuav txav mus nrog qhov ceev sib xws tom qab kev sib tsoo.
12. Lo lus nug: Tus coefficient ntawm kev them rov qab muaj feem cuam tshuam li cas rau kev sib tsoo tsis sib xws? Lus teb: Tus coefficient ntawm kev them rov qab, uas yog , ntsuas qhov "bounciness" ntawm kev sib tsoo. Rau kev sib tsoo tsis sib xws, �=0 .
13. Lo lus nug: Vim li cas kev sib tsoo tsis sib haum thiaj li ua rau muaj suab? Lus teb: Kev sib tsoo tuaj yeem ua rau muaj kev co hauv cov khoom sib tsoo, uas yuav ua rau muaj suab nthwv dej hauv qhov chaw ib puag ncig.
14. Lo lus nug: Lub zog gravitational potential puas yog ib qho tseem ceeb rau kev sib tsoo inelastic? Teb: Yog, tshwj xeeb tshaj yog tias kev sib tsoo ua rau muaj kev hloov pauv ntawm qhov siab lossis qhov chaw ntawm cov khoom, hloov lub zog kinetic mus ua lub zog gravitational potential.
15. Lo lus nug: Vim li cas cov pob roj hmab thiaj tsis sib tsoo zoo li qub, txawm tias lawv "bouncy" los xij? Lus teb: Cov pob roj hmab sib tsoo zoo li qub lossis ze li qub vim lawv feem ntau khaws lawv lub zog kinetic thiab rov qab los. Lawv tsis lo ua ke, uas yuav yog tus yam ntxwv ntawm kev sib tsoo zoo li qub.
16. Lo lus nug: Ob lub pob av nplaum mos puas tuaj yeem ua pov thawj tias muaj kev sib tsoo tsis sib haum xeeb? Teb: Yog, vim tias thaum ob lub pob av nplaum mos sib tsoo, lawv feem ntau lo ua ke thiab tsis rov qab los, uas yog tus yam ntxwv ntawm kev sib tsoo tsis sib haum xeeb.
17. Lo lus nug: Puas ua tau rau kev sib tsoo tsis sib luag yam tsis muaj suab lossis cua sov? Lus teb: Nws tsis tshua muaj, tab sis ua tau. Lub zog tuaj yeem raug tshem tawm hauv lwm txoj hauv kev tsis pom tseeb lossis khaws cia ua lub zog sab hauv.
18. Lo lus nug: Puas tuaj yeem thim rov qab qhov kev sib tsoo tsis sib xws? Lus teb: Feem ntau, kev sib tsoo tsis sib xws tsis tuaj yeem thim rov qab vim tias kev hloov pauv ntawm lub zog kinetic mus rau lwm daim ntawv ua rau nws nyuaj rau rov qab mus rau lub xeev pib.
19. Lo lus nug: Kev tiv thaiv ntawm huab cua cuam tshuam li cas rau kev sib tsoo tsis sib xws? Lus teb: Kev tiv thaiv ntawm huab cua tuaj yeem ua rau kev sib tsoo tsis sib xws ntau dua los ntawm kev tshem tawm qee lub zog kinetic ua cua sov.
20. Lo lus nug: Puas yog kev sib tsoo tsis sib luag muaj feem cuam tshuam rau kev tsim qauv kev nyab xeeb, xws li thaj chaw sib tsoo ntawm lub tsheb? Lus teb: Yog, thaj chaw sib tsoo hauv lub tsheb yog tsim los kom muaj kev sib tsoo tsis sib luag, nqus tau lub zog kinetic thiab txo cov zog uas ua rau cov neeg nyob hauv.
Kev sib tsoo tsis sib xws ua lub luag haujlwm tseem ceeb hauv kev nkag siab txog cov kev cai lij choj ntawm kev txuag physics thiab yog qhov tseem ceeb hauv ntau daim ntawv thov thiab kev tsim qauv kev nyab xeeb.
