1. Ib lub log uas muaj 1 'meter' radius nrawm nrawm sib npaug zos ntawm 2 rad/s2. Txheeb xyuas qhov kev nrawm ntawm lub kaum sab xis thiab cov qhov ceev ntawm lub kaum sab xis ntawm lub log, 2 vib nas this tom qab.
Paub:
Lub vojvoog (r) = 1 'meter'
Kev nrawm ntawm lub kaum sab xis (α)) = 2 rad/s2
SE pob: kev nrawm ntawm lub kaum sab xis thiab qhov ceev ntawm lub kaum sab xis tom qab 2 vib nas this.
Tshuaj:
(A) Kev nrawm ntawm lub kaum sab xis hauv 2 vib nas this
Lub kaum sab xis acceleration yog tas li, yog li tom qab 2 vib nas this, lub kaum sab xis acceleration ntawm lub log yog 2 rad/s2.
(B) Qhov ceev ntawm lub kaum sab xis hauv 2 vib nas this
Kev nrawm ntawm lub kaum sab xis 2 rad/s2 txhais tau tias qhov ceev ntawm lub kaum sab xis nce 2 radians/ob vib nas this txhua 1 vib nas this. Tom qab 1 vib nas this, qhov ceev ntawm lub kaum sab xis = 2 radians/ob vib nas this. Tom qab 2 vib nas this, qhov ceev ntawm lub kaum sab xis = 4 radians/ob vib nas this.
2. Ib lub khoom me me nrawm nrawm sib npaug zos thaum nws so mus txog 60 rpm hauv 10 vib nas this. Txheeb xyuas qhov loj ntawm qhov nrawm ntawm lub kaum sab xis!
Paub:
Qhov pib ntawm lub kaum sab xis (ω)o= 0 TZS
Qhov ceev kawg ntawm lub kaum sab xis (ωt) = 60 rpm = 60 revolutions / 60 vib nas this = 1 revolutions / vib nas this = 6,28 radians / vib nas this
Lub sijhawm luv (t) = 10 vib nas this
Xav tau: Kev nrawm ntawm lub kaum sab xis (α)
Tshuaj:

ωo = qhov pib ntawm lub kaum sab xis, ωt = qhov ceev kawg ntawm lub kaum sab xis, α = qhov kev nrawm ntawm lub kaum sab xis, t = lub sijhawm luv, θ = lub kaum sab xis.
ωt = ωo + α t
6.28 = 0 + α (10)
6.28 = 10 α
α = 6.28/10
α = 0.628 rad/s2
Qhov loj ntawm qhov kev nrawm ntawm lub kaum sab xis = 0.628 rad/s2
3. Ib yam khoom qeeb qeeb ntawm 20 rad/s mus rau 10 rad/s hauv 4 vib nas this. Txheeb xyuas qhov loj ntawm qhov kev nrawm ntawm lub kaum sab xis!
Paub:
Lub sijhawm luv (t) = 4 vib nas this
Qhov pib ntawm lub kaum sab xis (ωo ) = 20 rad/s
Qhov ceev kawg ntawm lub kaum sab xis (ωt) = 10 rad/s
xav : qhov loj ntawm qhov kev nrawm ntawm lub kaum sab xis (α))
Tshuaj:
ωt = ωo + α t
10 = 20 + α (4)
10 - 20 = 4 α
-10 = 4 α
α = -10 / 4
α = – 2.5 rad/s2
Qhov loj ntawm qhov kev nrawm ntawm lub kaum sab xis yog -2.5 rad/s2Lub cim tsis zoo txhais tau tias yam khoom tab tom qeeb qeeb. Kev nrawm = qhov ceev ntawm lub kaum sab xis nce ntxiv, kev qeeb qeeb = qhov ceev ntawm lub kaum sab xis txo qis.
4. Ib yam khoom raug nrawm rau 2 vib nas this los ntawm 10 rad/s mus rau 2 rad/s2Txheeb xyuas lub kaum sab xis uas qhov khoom puag ncig!
Paub:
qhov pib ntawm lub kaum sab xis (ωo ) = 10 rad/s
qhov kev nrawm ntawm lub kaum sab xis (α) = 2 rad/s2
lub sijhawm luv (t) = 2 vib nas this
Xav tau: lub kaum sab xis (θ)
Tshuaj:
θ = ωo + ½ α t2
θ = (10)(2) + ½ (2)(2)2)
θ = 20 + (1)(4) = 20 + 4
θ = 24 radians
5. Lub log tsheb qeeb qeeb los ntawm 20 rad/s mus rau so tom qab ncig 20 radians. Txheeb xyuas qhov loj ntawm qhov kev nrawm ntawm lub kaum sab xis ntawm lub log!
Paub:
qhov pib ntawm lub kaum sab xis (ωo) = 20 rad/s
qhov ceev kawg ntawm lub kaum sab xis (ωt= 0 TZS
Lub kaum sab xis (θ) = 20 radians
Xav tau: qhov loj ntawm qhov kev nrawm ntawm lub kaum sab xis (α)
Tshuaj:
ωt2 = ωo2 + 2 α θ
0 = 202 + 2 α (20)
0 = 400 + 40 α
400 = – 40 α
α = – 400 / 40
α = – 10 rad/s2
6. Ib tug pas nrig PQ uas ntev 60 cm tig ib ncig ntawm qhov chaw Q ua lub axis ntawm kev tig thiab PQ ua lub vojvoog radius. Tus pas nrig PQ tau nrawm los ntawm qhov so mus rau 0.3 rad/s.2Yog tias qhov chaw pib ntawm lub kaum sab xis yog 0, qhov ceev ntawm qhov taw tes P ntawm t = 10 vib nas this yog dab tsi.
Paub:
Qhov ntev ntawm tus pas nrig PQ = lub vojvoog ntawm lub vojvoog (r) = 60 cm = 60/100 m = 0.60 m
Qhov pib ntawm lub kaum sab xis (ω)o) = 0 rad/s
Kev nrawm ntawm lub kaum sab xis (α) = 0.3 rad s-2
Qhov pib ntawm lub kaum sab xis (θ)o= 0 TZS
Xav tau: Qhov ceev ntawm kab (v) ntawm qhov chaw P ntawm t = 10 vib nas this
Tshuaj:
Qhov ceev kawg ntawm lub kaum sab xis tom qab 10 vib nas this:
ωt = ωo + α t = 0 rad/s + (0.3 rad/s-2)(10 s) = 3 rad/s
Qhov kawg linear ceev tom qab 10 vib nas this:
v = r ω = (0.6 m)(3 rad/s) = 1.8 m/s
7. Ib yam khoom tig nrog qhov ceev pib ntawm 4 rad/s thiab qhov kev nrawm ntawm lub kaum sab xis yog 0.5 rad/s2. Qhov ceev ntawm yam khoom tom qab 4 vib nas this yog dab tsi.
Paub:
Qhov pib ntawm lub kaum sab xis (ω)o) = 4 rad/s
Kev nrawm ntawm lub kaum sab xis (α) = 0.5 rad/s2
Lub sijhawm luv (t) = 4 vib nas this
Xav tau: Qhov ceev ntawm cov khoom tom qab 4 vib nas this (ω)t)
Tshuaj:
ωt = ωo + α t
ωt = 4 + (0.5)(4)
ωt = 4 + 2
ωt = 6 rad/s
8. A Lub moos phab ntsa uas muaj txoj kab uas hla 10 cm muaj peb lub koob, txhua lub los qhia cov teev, feeb thiab vib nas this. Kev sib piv ntawm tus naj npawb ntawm cov voj voog ntawm lub koob teev: lub koob feeb: lub koob thib ob.
A. 1: 3: 180
B. 1: 12: 720
C. 4: 12: 180
D. 4: 12: 720
Paub:
1 teev = 60 feeb
12 teev = (12) (60 feeb) = 720 feeb
Qhov ceev ntawm lub koob teev = 1 lub voj voog / 12 teev = 1 lub voj voog / 720 feeb
Qhov ceev ntawm lub koob feeb = 1 tig / 1 teev = 1 tig / 60 feeb
Qhov ceev ntawm lub koob thib ob = 1 revolution / 1 feeb
SE pob: Kev sib piv ntawm tus naj npawb ntawm cov voj voog ntawm lub koob teev: lub koob feeb: lub koob thib ob
Tshuaj:
Qhov sib npaug ntawm kev txav mus los ncig:
Qhov ceev ntawm lub kaum sab xis = tus naj npawb ntawm kev hloov pauv / lub sijhawm sib nrug
Tus naj npawb ntawm kev tig = qhov ceev ntawm lub kaum sab xis x lub sijhawm sib nrug
Hauv tib lub sijhawm, piv txwv li, 1 feeb, muaj pes tsawg lub voj voog ntawm lub koob teev, koob feeb, thiab koob thib ob.
Tus naj npawb ntawm kev tig ntawm lub koob teev = qhov ceev ntawm lub kaum sab xis x lub sijhawm = (1 kev tig / 720 feeb) (1 feeb) = 1/720 kev tig
Tus naj npawb ntawm kev tig ntawm lub koob feeb = qhov ceev ntawm lub kaum sab xis x lub sijhawm = (1 kev tig / 60 feeb) (1 feeb) = 1/60 kev tig
Tus naj npawb ntawm kev tig ntawm lub koob thib ob = qhov ceev ntawm lub kaum sab xis x lub sijhawm = (1 kev tig / 1 feeb) (1 feeb) = 1/1 kev tig
Kev sib piv ntawm ntau qhov kev hloov pauv:
Tus naj npawb ntawm kev tig ntawm lub koob teev: tus naj npawb ntawm kev tig ntawm lub koob feeb: tus naj npawb ntawm kev tig ntawm lub koob thib ob.
1/720 : 1/60 : 1/1
1/720 : 12/720 : 720/720
1: 12: 720
Cov lus teb yog B.
9. Ib lub pob khi nrog ib txoj hlua. Lub pob tig kom nws txav mus rau hauv ib lub voj voog sib luag rau saum npoo ntawm lub ntiaj teb. Hauv qhov kev txav no, lub pob nrawm dua vim tias…..
A. Txhuam ntawm huab cua
B. Nyhav ntawm lub pob
C. Lub zog nruj
D. Lub zog ntawm lub ntiajteb txawj nqus
Tshuaj:
Newton txoj cai thib ob ntawm kev txav mus los hais tias ib yam khoom raug nrawm yog tias muaj lub zog tshwm sim. Lub pob txuas nrog txoj hlua thiab thaum txoj hlua tig, lub pob kuj tig. Thaum lub pob tig (lub pob txav mus rau hauv lub voj voog), lub pob dhau los ua qhov nrawm ntawm centripetal. Tag nrho cov khoom txav mus los yog qhov nrawm ntawm centripetal ncig. Kev nrawm ntawm centripetal tshwm sim los ntawm lub zog centripetalLub zog centripetal rau rooj plaub no yog lub zog nruj.
Cov lus teb yog C.
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- Kev hloov pauv cov chav ntawm lub kaum sab xis piv txwv cov teeb meem nrog cov kev daws teeb meem
- Cov teeb meem thiab kev daws teeb meem ntawm cov qauv angular displacement thiab linear displacement
- Cov teeb meem piv txwv ntawm angular velocity thiab linear velocity nrog cov kev daws teeb meem
- Cov teeb meem piv txwv ntawm kev nrawm nrawm thiab kev nrawm nrawm linear nrog cov kev daws teeb meem
- Cov teeb meem piv txwv ntawm kev txav mus los sib npaug nrog cov kev daws teeb meem
- Cov teeb meem ntawm cov qauv centripetal acceleration nrog cov kev daws teeb meem
- Cov teeb meem piv txwv ntawm kev txav mus los tsis sib xws nrog cov kev daws teeb meem
nyeem ntxiv