7 Piv txwv ntawm cov lus nug txog kev nrawm ntawm centripetal
1. Ib lub pob zeb raug khi rau ntawm txoj hlua thiab tom qab ntawd tig kab rov tav kom txog thaum lub pob zeb tig lub kaum sab xis 360°.o txhua 1 vib nas this. Yog tias qhov ntev ntawm txoj hlua yog 20 cm, txiav txim siab qhov loj ntawm qhov kev nrawm ntawm lub centripetal ntawm cov khoom!
Kev Sib Tham
Nws yog paub :
Lub kaum sab xis ceev (ω) = 360o/ob vib nas this = 1 kev tig / ob vib nas this = 6,28 radians/ob vib nas this
Qhov ntev ntawm txoj hlua = lub vojvoog (r) ntawm txoj kev voj voog = 20 cm = 0,2 meters
Nug : kev nrawm ntawm lub centripetal (as)
Jawb :
2. Ib lub log uas muaj lub vojvoog ntawm 30 cm tig ntawm qhov ceev ntawm 180 rpm. Txheeb xyuas qhov kev nrawm ntawm lub centripetal ntawm ib qho chaw ntawm ntug ntawm lub log!
Kev Sib Tham
Nws yog paub :
Lub vojvoog (r) ntawm lub log = 30 cm = 0,3 meters
Qhov ceev ntawm lub kaum sab xis (ω) = 180 lub voj voog / 60 vib nas this = 3 lub voj voog / vib nas this = (3) (6,28 radians) / vib nas this = 18,84 radians / vib nas this
Nug : kev nrawm ntawm lub centripetal (as) ntawm r = 0,3 meters
Jawb :
3. Ib tug neeg sib tw tsav lub tsheb ncig ib lub voj voog uas muaj qhov nkhaus ntawm 50 meters. Yog tias qhov ceev ntawm lub tsheb yog 72 km / teev, qhov kev nrawm ntawm lub tsheb yog dab tsi?
Kev Sib Tham
Nws yog paub :
Lub vojvoog (r) = 50 meters
Ceev (v) = 72 km/teev = (72)(1000 meters) / 3600 vib nas this = 20 meters/ vib nas this
Nug : qhov loj ntawm qhov kev nrawm ntawm centripetal (a)s)
Jawb :
Qhov loj ntawm lub tsheb qhov kev nrawm centripetal:
as = v2 / r = 202 / 50 = 400 / 50 = 8 m/s2
4. Lub tsheb tab tom tsav ntawm ib qho nkhaus nrog qhov radial acceleration ntawm 10 m/s2, qhov twg qhov no yog qhov siab tshaj plaws ntawm lub tsheb uas lub tsheb tuaj yeem ua tiav yam tsis plam tawm ntawm txoj kev. Yog tias qhov ceev ntawm lub tsheb yog 108 km / h, qhov nkhaus ntawm qhov nkhaus yog dab tsi kom lub tsheb tsis plam?
Kev Sib Tham
Nws yog paub :
Kev nrawm ntawm lub centripetal (a)s) = 10 m/s2
Qhov ceev ntawm lub tsheb (v) = 108 km/teev = (108)(1000) / 3600 = 30 meters/feeb
Nug : vojvoog (r)
Jawb :
Lub zog ntawm curvature ntawm lub qhov:
r = v2 / ibs
r = 302 / 10 = 900 / 10 = 90 meters
5. Cov Lus Nug Txog Kev Xeem Thoob Tebchaws Xyoo 2003/2004
Ib daim duab qhia txog kev sib raug zoo ntawm kev nrawm ntawm lub centripetal (a s ) thiab qhov ceev ntawm txoj kab (v) hauv kev txav mus los ib puag ncig...
Kev Sib Tham
Cov mis ntawm kev ua kom nrawm ntawm centripetal:
Kev piav qhia: a s = centripetal acceleration, v = linear velocity, r = deb ntawm lub axis ntawm kev tig.
Peb tshawb nrhiav kev sib raug zoo ntawm kev nrawm ntawm lub centripetal (a s ) thiab qhov ceev ntawm lub linear (v) kom qhov deb ntawm lub axis ntawm kev tig (r) yog qhov tas li. Xav tias r = 1.
Tus nqi ntawm v nce linearly, tus nqi ntawm as nce exponentially.
Cov lus teb yog lawm yog A.
6. Cov Lus Nug Txog Kev Xeem Hauv Tebchaws rau SMA/MA Physics U-ZC-2013/2014 No. 4
Ib lub pob zeb marble raug tig hauv ib lub tais puag ncig uas muaj txoj kab uas hla ntawm 1 m. Yog tias lub pob zeb marble tig ib ncig ntawm ntug ntawm lub tais ntawm qhov ceev ntawm lub kaum sab xis tas li ntawm 50 rpm, ces qhov ceev linear thiab centripetal acceleration ntawm lub pob zeb marble yog….
A. 50 ms -1 thiab 2500 ms -2
B. 5π ms -1 thiab 25π 2 ms -2
C. 5π/3 ms -1 thiab 25π 2 /18 ms -2
D. 5π/6 ms -1 thiab 25π 2 /18 ms -2
E. 5π/12 ms -1 thiab 25π 2 /36 ms -2
Kev Sib Tham
Nws paub tias:
Lub voj voog txoj kab uas hla (D) = 1 'meter'
Lub vojvoog ntawm lub voj voog (r) = 0,5 meters
Lub kaum sab xis ceev (ω) = 50 rpm = 50 revolutions / 1 feeb
1 lub voj voog = 2π radians
50 lub voj voog = 50 (2π radians) = 100π radians
1 feeb = 60 vib nas this
Lub zog ntawm lub kaum sab xis (ω) = 100π radians / 60 vib nas this = (10π/6) radians/ob vib nas this
Lus Nug: Linear velocity (v) thiab centripetal acceleration (a s )
Lus teb:
Qhov ceev ncaj (v):
v = r ω = (0,5)(10π/6) = 5π/6 m/s
Kev nrawm ntawm lub centripetal (a)s):
a s = v 2 /r = (5π/6) 2 : 0,5 = 25π 2 /36 : 0,5 = (25π 2 / 36)(1/0,5)
ib s = (25π 2 /18) m/s 2
Cov lus teb yog D.
7. Cov Lus Nug Xeem Thoob Tebchaws Xyoo 2007/2008 P4 No. 6
Ib yam khoom txav mus rau qhov ceev tas li v raws txoj kev voj voog nrog lub vojvoog R nrog kev nrawm ntawm centripetal (a s ). Yuav kom qhov kev nrawm ntawm centripetal yog ob npaug ntawm thawj, ces...
A. v yog ua 4 zaug thiab R yog ua 2 zaug dua
B. v yog ua 2 zaug thiab R yog ua 4 zaug dua
C. v yog ua 2 zaug thiab R yog ua 2 zaug dua
D. v tseem nyob thiab R raug ob npaug dua
E. v raug ob npaug dua thiab R tseem nyob
Kev Sib Tham
