Kev sib tsoo ib nrab elastic
Hauv kev sib tsoo uas muaj qee qhov elastic, txoj cai ntawm kev txuag lub zog momentum siv tau, thaum txoj cai txuag lub zog kinetic tsis siv tau. Thaum lub sijhawm sib tsoo tshwm sim, qee lub zog kinetic raug hloov mus ua lub zog suab, lub zog cua sov, thiab lub zog sab hauv. Kev siv lo lus elastic qhia tias tom qab kev sib tsoo, ob yam khoom tsis lo ua ke tab sis dhia tawm.
Ib qho piv txwv ntawm kev sib tsoo ib nrab yog qhov kev sib tsoo ib-seem ntawm ob lub pob zeb lossis ob lub pob pas dej ua ke.
Piv txwv lo lus nug 1.
Cov khoom A thiab B uas hnyav 1 kg thiab 2 kg, feem ntau txav mus rau hauv kev taw qhia sib txawv ntawm qhov ceev ntawm 4 m/s thiab 2 m/s, feem ntau thiab sib tsoo hauv kev sib tsoo ib nrab elastic. Yog tias tom qab sib tsoo khoom A txav mus rau qhov ceev ntawm 2 m/s, qhov ceev ntawm khoom B yog dab tsi?
Paub:
m A = 1 kg, m B = 2 kg, v A = 4 m/s (xav tias sab xis), v B = -2 m/s (xav tias sab laug), v A ' = – 2 m/s
Xav tau : v B '
Tshuaj:
m A v A + m B v B = m A v A ' + m B v B '
(1 kg)(4 m/s) + (2 kg)(-2 m/s) = (1 kg)(-2 m/s) + (2 kg)(v B ')
4 kg m/s - 4 kg m/s = -2 kg m/s + (2 kg) v B '
0 = – 2 kg m/s + (2 kg)(v B ')
-2 kg m/s = – 2 kg v B '
vB ' = 1 m/s
Tom qab sib tsoo, khoom B txav mus rau qhov ceev ntawm 1 m/s (xav tias sab xis) thiab khoom A txav mus rau qhov ceev ntawm 2 m/s (xav tias sab laug)
Piv txwv lo lus nug 2.
Cov khoom A thiab B uas muaj qhov hnyav ntawm 4-kg thiab 5-kg mus ze rau ib leeg hauv qhov kev taw qhia sib txawv, raws li pom hauv daim duab hauv qab no. Tom qab kev sib tsoo, ob qho khoom tig rov qab nrog qhov ceev ntawm A = 4 ms -1 thiab qhov ceev ntawm B = 2 ms - 1. Qhov ceev ntawm cov khoom B ua ntej kev sib tsoo yog dab tsi?
Paub:
Qhov hnyav ntawm yam khoom A (mA) = 4 kg
Qhov hnyav ntawm yam khoom B (mB ) = 5 kg
Qhov ceev ntawm yam khoom A ua ntej sib tsoo (v A ) = 6 m/s
Qhov ceev ntawm yam khoom A tom qab sib tsoo (v A ') = 4 m/s
Qhov ceev ntawm yam khoom B tom qab sib tsoo (v B ') = -2 m/s
Cov cim ntxiv thiab cov cim rho qhia tias ob qho khoom txav mus rau hauv cov kev taw qhia sib txawv.
Xav tau: Qhov ceev ntawm yam khoom B ua ntej sib tsoo (v B )
Tshuaj:
m A v A + m B v B = m A v A ' + m B v B '
(4)(6) + (5)(-2) = (4)(4) + (5)(vB ' )
24 – 10 = 16 + 5(vB ' )
14 – 16 = 5 (vB ' )
-2 = 5 (vB ' )
vB ' = -2/5
vB ' = -0.4
Lub cim rho tawm qhia tias qhov kev taw qhia ntawm yam khoom tom qab kev sib tsoo txawv ntawm qhov kev taw qhia ua ntej kev sib tsoo.
Piv txwv lo lus nug 3.
Ob yam khoom uas muaj tib lub cev hnyav sib ze li pom hauv daim duab hauv qab no.
Yog tias v 2 ' yog qhov ceev ntawm yam khoom (2) tom qab kev sib tsoo mus rau sab xis nrog qhov ceev ntawm 5 ms -1 , qhov ceev ntawm yam khoom ib v 1 ' (1) tom qab kev sib tsoo yog dab tsi?
Paub:
Qhov hnyav ntawm txhua yam khoom = m
Qhov ceev ntawm yam khoom 1 ua ntej sib tsoo (v 1 ) = 8 m/s
Qhov ceev ntawm yam khoom 2 ua ntej sib tsoo (v 2 ) = 10 m/s
Qhov ceev ntawm yam khoom 2 tom qab sib tsoo (v 2 ') = 5 m/s
Xav tau: Qhov ceev ntawm yam khoom 1 tom qab sib tsoo (v 1 ')
Tshuaj:
m 1 v 1 + m 2 v 2 = m 1 v 1 ' + m 2 v 2 '
m (v 1 + v 2 ) = m (v 1 ' + v 2 ' )
v 1 + v 2 = v 1 ' + v 2 '
8 + 10 = v1 ' + 5
18 = v1 ' + 5
v 1 ' = 18-5
v 1 ' = 13 m/s
20 cov lus nug thiab lus teb txog kev sib tsoo ib nrab elastic:
1. Lo lus nug: Kev sib tsoo ib nrab elastic yog dab tsi? Lus teb: Kev sib tsoo ib nrab elastic yog qhov uas qee lub zog kinetic raug khaws cia, tab sis tsis yog txhua yam. Cov khoom rov qab los ntawm ib leeg tab sis tsis nrog lawv lub zog kinetic pib tag nrho.
2. Lo lus nug: Kev sib tsoo uas ib nrab elastic txawv li cas ntawm kev sib tsoo uas elastic tag nrho? Lus teb: Hauv kev sib tsoo uas elastic tag nrho, lub zog kinetic tag nrho raug khaws cia, thaum nyob rau hauv kev sib tsoo uas ib nrab elastic, tsuas yog ib feem ntawm lub zog kinetic raug khaws cia.
3. Lo lus nug: Dab tsi tseem khaws cia rau hauv kev sib tsoo uas ib nrab elastic? Lus teb: Lub zog tseem khaws cia rau hauv txhua hom kev sib tsoo, suav nrog cov uas ib nrab elastic.
4. Lo lus nug: Tus coefficient of restitution, , siv li cas los piav qhia txog qhov elasticity ntawm kev sib tsoo? Lus teb: Rau kev sib tsoo ib nrab elastic, 0<�<1 Qhov ze dua yog rau 1, qhov elastic ntau dua qhov kev sib tsoo.
5. Lo lus nug: Tus coefficient ntawm kev rov qab los puas tuaj yeem loj dua 1? Lus teb: Tsis yog. Tus coefficient ntawm kev hloov pauv ntau dua 1 yuav txhais tau tias muaj zog kinetic ntau dua tom qab kev sib tsoo dua li ua ntej, uas ua txhaum kev txuag hluav taws xob.
6. Lo lus nug: Vim li cas ho tsis khaws tag nrho lub zog kinetic hauv kev sib tsoo ib nrab elastic? Lus teb: Qee lub zog kinetic raug hloov mus ua lwm hom, xws li suab, cua sov, lossis kev hloov pauv ntawm cov khoom.
7. Lo lus nug: Koj yuav ua li cas thiaj paub qhov ntau ntawm lub zog kinetic uas khaws cia rau hauv kev sib tsoo uas ib nrab elastic? Lus teb: Los ntawm kev sib piv tag nrho lub zog kinetic ua ntej thiab tom qab kev sib tsoo.
8. Lo lus nug: Puas yog kev sib tsoo uas ib nrab elastic yeej ib txwm tsim suab? Lus teb: Tsis yog txhua lub sijhawm, tab sis suab tuaj yeem tsim tawm vim yog kev co los ntawm kev sib tsoo.
9. Lo lus nug: Yuav ua li cas rau lub zog kinetic uas tsis tau khaws cia rau hauv kev sib tsoo ib nrab elastic? Lus teb: Feem ntau nws hloov mus ua lwm hom zog xws li cua sov, suab, lossis lub zog muaj peev xwm vim yog kev hloov pauv.
10. Lo lus nug: Cov khoom siv sib xyaw ua ke cuam tshuam li cas rau qhov elasticity ntawm kev sib tsoo? Lus teb: Qee cov khoom siv, xws li roj hmab, feem ntau yuav muaj kev sib tsoo elastic dua, thaum lwm tus, zoo li av nplaum, feem ntau yuav tsis ywj. Txawm li cas los xij, feem ntau ntawm kev sib tsoo hauv ntiaj teb tiag tiag yog ib feem elastic vim yog cov khoom ntawm cov khoom thiab lwm yam.
11. Lo lus nug: Ob lub pob hlau puas tuaj yeem ua pov thawj tias muaj kev sib tsoo ib nrab elastic? Teb: Yog. Txawm hais tias cov pob hlau zoo li muaj kev sib tsoo yuav luag zoo meej elastic, feem ntau muaj kev poob zog me ntsis, ua rau nws ib nrab elastic.
12. Lo lus nug: Puas yog lub ntiaj teb sib tsoo nrog lub hnub qub poob uas suav tias yog ib feem ntawm elastic? Lus teb: Feem ntau, yog. Qhov kev cuam tshuam tsis txuag tag nrho lub zog kinetic vim qee qhov raug hloov mus ua cua sov, suab, thiab tsim lub qhov av qeeg.
13. Lo lus nug: Koj puas muaj peev xwm muaj kev sib tsoo ib nrab elastic hauv lub tshuab nqus tsev? Teb: Yog. Txawm tias tsis muaj cua tiv thaiv, cov khoom sab hauv ntawm cov lub cev sib tsoo tuaj yeem ua rau poob zog.
14. Lo lus nug: Cov zog sab nraud, xws li kev sib txhuam, cuam tshuam li cas rau qhov elasticity ntawm kev sib tsoo? Lus teb: Cov zog sab nraud tuaj yeem ua rau lub zog kinetic ntau dua, ua rau kev sib tsoo tsis ywj pheej ntau dua.
15. Lo lus nug: Puas muaj kev siv tau tiag tiag uas kev nkag siab txog kev sib tsoo uas ib feem ntawm elastic yog qhov tseem ceeb? Lus teb: Yog, hauv kev ua kis las, kev tsim kho, thiab kev tshuaj xyuas kev sib tsoo tsheb, kev nkag siab txog kev sib tsoo uas ib feem ntawm elastic tuaj yeem yog qhov tseem ceeb.
16. Lo lus nug: Vim li cas cov tuam txhab tsim tsheb thiaj kawm txog kev sib tsoo uas ib nrab ywj pheej? Lus teb: Txhawm rau tsim cov tsheb uas tuaj yeem nqus tau lub zog cuam tshuam zoo, tiv thaiv cov neeg nyob hauv tsheb thaum muaj kev sib tsoo.
17. Lo lus nug: Puas tuaj yeem suav tias kev sib cuam tshuam ntawm cov khoom me me ntawm theem quantum yog ib feem elastic? Teb: Yog. Txawm hais tias quantum mechanics qhia txog cov xwm txheej tshiab, cov khoom me me tseem tuaj yeem dhau los ua kev sib cuam tshuam qhov twg tsis yog txhua lub zog kinetic raug khaws cia.
18. Lo lus nug: Kev sib cuam tshuam ntawm cov molecule muaj feem cuam tshuam li cas rau kev sib tsoo ib nrab elastic? Lus teb: Cov molecules tuaj yeem dhau los ua kev sib tsoo ib nrab elastic thaum lawv ntaus ib leeg, hloov qee lub zog mus rau hauv kev co lossis kev tig ntawm cov molecule.
19. Lo lus nug: Puas yog lub pob basketball dhia rau ntawm lub tshav pob qhia tau tias muaj kev sib tsoo ib nrab ntawm elastic? Teb: Yog. Qee lub zog ploj mus ua suab thiab rau qhov me me ntawm lub pob deformation, ua rau kev sib tsoo ib nrab elastic.
20. Lo lus nug: Qhov kub thiab txias cuam tshuam li cas rau qhov elasticity ntawm kev sib tsoo hauv cov pa roj? Lus teb: Thaum qhov kub thiab txias nce ntxiv, cov pa roj molecule txav mus sai dua thiab tuaj yeem sib tsoo ntau dua. Txawm li cas los xij, qhov elasticity ntawm cov kev sib tsoo no nyob ntawm cov khoom molecular thiab tsis cuam tshuam ncaj qha nrog qhov kub thiab txias.
Kev nkag siab txog kev sib tsoo ib nrab elastic muab kev nkag siab txog ntau yam xwm txheej hauv ob qho tib si kev paub txhua hnub thiab kev tshwj xeeb hauv physics thiab engineering.
