Zitsanzo 5 za Chilamulo cha Bernoulli
1 P1 dani v1 ndi kupanikizika ndi liwiro la mpweya pamwamba pa phiko, P2 dani v2 ndi kuthamanga ndi kuthamanga kwa mpweya pansi pa phiko. Kuti ndege ikwere, zinthu zimakhala bwino...
A. P1 =P2 dani v1 = v2
B. P1 < P2 dani v1 > v2
C. P1 < P2 dani v1 < v2
D.P1 > P2 dani v1 > v2
E.P1 > P2 dani v1 < v2
Kukambirana:
Amadziwika kuti:
P1 = Kuthamanga kwa mpweya pamapiko
P2 = Kuthamanga kwa mpweya pansi pa mapiko
v1 = liwiro la mpweya pamapiko
v2 = liwiro la mpweya pansi pa mapiko
Anafunsa :
Kodi zinthu zili bwanji kuti ndege ikwere kapena kuti ikwere mmwamba?
Yankhani :
Lamulo la Bernoulli kapena kutchedwa molondola kwambiri Mfundo ya Bernoulli amanena kuti ngati liwiro la madzi lili lalikulu, kuthamanga kwa madzi kumakhala kochepa, ndipo mosemphanitsa, ngati liwiro la madzi lili lochepa, kuthamanga kwa madzi kumakhala kwakukulu. Madzi ndi zinthu zomwe zimatha kuyenda. Zitsanzo za madzi ndi mpweya ndi madzi.
Ngati liwiro la mpweya lili lalikulu, kuthamanga kwa mpweya kumakhala kochepa, mosiyana, ngati liwiro la mpweya lili lochepa, kuthamanga kwa mpweya kumakhala kwakukulu.
Pamene liwiro la mpweya pamwamba pa phiko lili lalikulu kuposa liwiro la mpweya pansi pa phiko, kuthamanga kwa mpweya pamwamba pa phiko kumakhala kochepa kuposa kuthamanga kwa mpweya pansi pa phiko. Chifukwa chakuti kuthamanga kwa mpweya pansi pa phiko kuli kwakukulu, kukankha kwa mpweya pansi pa phiko nakonso kumakhala kwakukulu. Mosiyana ndi zimenezi, kuthamanga kwa mpweya pamwamba pa phiko kumakhala kochepa, kotero kukankha kwa mpweya pamwamba pa phiko nakonso kumakhala kochepa (P = F/A - kuthamanga kwakukulu, P, mphamvu yaikulu, F).
Kukankha kwa mpweya pansi pa phiko ndi kwakukulu, kukankha kwa mpweya pamwamba pa phiko ndi kochepa, kotero pali mphamvu yochokerapo kapena mphamvu yonse yomwe imalunjika mmwamba. Mphamvu yonseyi imatsogozedwa mmwamba zomwe zimapangitsa kuti ndegeyo ikwere..
Jadi zofunikira kuti ndege inyamuke ndi P1 < P2 ndi v1 > v2
Yankho lolondola ndi B.
2.
Mu chithunzichi, madzi amapopedwa ndi compressor pa mphamvu ya 120 kPa kulowa mu chitoliro cha pansi (1) ndipo amayenderera mmwamba pa liwiro la 1 m/s.-1 (g = 10 ms-2 ndipo kuchuluka kwa madzi ndi 1000 kg.m-3). Kuthamanga kwa madzi mu chitoliro chapamwamba (II) ndi….
A. 52,5 kPa
B. 67,5 kPa
C. 80,0 kPa
D. 92,5 kPa
E. 107,5 kPa
Zokambirana
Amadziwika kuti:
Chitoliro chachikulu (r)1) = 12 cm
Chitoliro chaching'ono (r)2) = 6 cm
Kupanikizika kwa madzi m'mapaipi akuluakulu (p)1) = 120 kPa = Ma Pascal 120.000
Liwiro la madzi m'mapaipi akuluakulu (v)1) = 1 ms-1
Kutalika kwa chitoliro chachikulu (h)1) = 0 m
Kutalika kwa chitoliro chaching'ono (h)2) = 2 m
Kuthamanga chifukwa cha mphamvu yokoka (g) = 10 ms-2
Kuchuluka kwa madzi (ρ) = 1000 kg.m-3
Anafunsa kuti: Kupanikizika kwa madzi mu chitoliro 2 (p)2)
Yankho:
Liwiro la madzi mu chitoliro 2 limawerengedwa pogwiritsa ntchito Continuity Equation:
A1 v1 =A2 v2
(π r12)(v1) = (π r22)(v2)
(r12)(v1) = (r22)(v2)
(122)(1 m/s) = (62)(v2)
144 = 36 v2
v2 = 144/36
v2 = 4 m/s
Kupanikizika kwa madzi mu chitoliro 2 kumawerengedwa pogwiritsa ntchito equation ya Bernoulli:
120.000 + ½ (1000)(12) + (1000)(10)(0) = p2 + ½ (1000)(42) + (1000)(10)(2)
120.000 + ½ (1000)(1) + (1000)(10)(0) = p2 + ½ (1000)(16) + (1000)(10)(2)
120.000 + 500 + 0 = p2 + (500)(16) + 20.000
120.000 + 500 = p2 + 8000 + 20.000
120.500 = p2 + 28.000
p2 = 120.500-28.000
p2 = Ma Pascal 92.500
p2 = 92,5 kPa
Yankho lolondola ndi D.
3. Yang'anani chithunzi chotsatirachi!
Chitoliro chachikulu chili pamtunda wa mamita 5 kuchokera pansi ndipo chitoliro chaching'ono chili pamtunda wa mita 1 kuchokera pansi. Kuthamanga kwa madzi mu chitoliro chachikulu ndi 36 km/h.-1 ndi kupanikizika kwa 9,1 x 105 Pa, pomwe kupanikizika mu chitoliro chaching'ono ndi 2.105 Pa, ndiye kuti liwiro la madzi mu chitoliro chaching'ono ndi…. (kuchuluka kwa madzi = 103 kg.m-3)
A. 10 ms-1
B. 20 ms-1
C. 30 ms-1
D. 40 ms-1
E. 50 ms-1
Zokambirana
Amadziwika kuti:
Kupanikizika kwa madzi m'mapaipi akuluakulu (p)1) = 9,1 x 105 Pascal = Ma Pascal 910.000
Kupanikizika kwa madzi m'mapaipi ang'onoang'ono (p)2) = 2 x 105 Pascal = Ma Pascal 200.000
Liwiro la madzi m'mapaipi akuluakulu (v)1) = 36 km/h = 36(1000)/(3600) = 36000/3600 =10 m/s
Kutalika kwa chitoliro chachikulu (h)1) = -4 mamita
Kutalika kwa chitoliro chaching'ono (h)2) = mamita 0
Kuthamanga chifukwa cha mphamvu yokoka (g) = 10 ms-2
Kuchuluka kwa madzi (ρ) = 1000 kg.m-3
Anafunsa kuti: Liwiro la madzi mu chitoliro chaching'ono (v)2)
Yankho:
Liwiro la madzi mu chitoliro chaching'ono (v)2) amawerengedwa pogwiritsa ntchito equation ya Bernoulli:
910.000 + ½ (1000)(102) + (1000) (10) (0) = 200.000 + ½ (1000) (v22) + (1000)(10)(-4)
910.000 + 50.000 + 0 = 200.000 + 500 v22 - 40.000
960.000 = 160.000 + 500 v22
800.000 = 500 v22
800.000 / 500 = v22
1600 = v22
v2 = √1600
v2 = 40 m/s
Yankho lolondola ndi D.
4. Mu chithunzichi, madzi amapopedwa ndi compressor pa mphamvu ya 120 kPa kulowa mu chitoliro cha pansi (1) ndipo amayenderera mmwamba pa liwiro la 1 m/s.-1 (g = 10 ms-2 ndipo kuchuluka kwa madzi ndi 1000 kg.m-3). Kuthamanga kwa madzi mu chitoliro chapamwamba (II) ndi….
A. 52,5 kPa
B. 67,5 kPa
C. 80,0 kPa
D. 92,5 kPa
E. 107,5 kPa
Zokambirana
Amadziwika kuti:
Chitoliro chachikulu (r)1) = 12 cm
Chitoliro chaching'ono (r)2) = 6 cm
Kupanikizika kwa madzi m'mapaipi akuluakulu (p)1) = 120 kPa = Ma Pascal 120.000
Liwiro la madzi m'mapaipi akuluakulu (v)1) = 1 ms-1
Kutalika kwa chitoliro chachikulu (h)1) = 0 m
Kutalika kwa chitoliro chaching'ono (h)2) = 2 m
Kuthamanga chifukwa cha mphamvu yokoka (g) = 10 ms-2
Kuchuluka kwa madzi (ρ) = 1000 kg.m-3
Anafunsa kuti: Kupanikizika kwa madzi mu chitoliro 2 (p)2)
Yankho:
Liwiro la madzi mu chitoliro 2 limawerengedwa pogwiritsa ntchito Continuity Equation:
A1 v1 =A2 v2
(π r12)(v1) = (π r22)(v2)
(r12)(v1) = (r22)(v2)
(122)(1 m/s) = (62)(v2)
144 = 36 v2
v2 = 144/36
v2 = 4 m/s
Kupanikizika kwa madzi mu chitoliro 2 kumawerengedwa pogwiritsa ntchito equation ya Bernoulli:
120.000 + ½ (1000)(12) + (1000)(10)(0) = p2 + ½ (1000)(42) + (1000)(10)(2)
120.000 + ½ (1000)(1) + (1000)(10)(0) = p2 + ½ (1000)(16) + (1000)(10)(2)
120.000 + 500 + 0 = p2 + (500)(16) + 20.000
120.000 + 500 = p2 + 8000 + 20.000
120.500 = p2 + 28.000
p2 = 120.500-28.000
p2 = Ma Pascal 92.500
p2 = 92,5 kPa
Yankho lolondola ndi D.
5. Yang'anani chithunzi chotsatirachi! Malo a chitoliro chachikulu ndi mamita 5 kuchokera pansi ndipo chitoliro chaching'ono chili mamita 1 kuchokera pansi. Liwiro la kuyenda kwa madzi mu chitoliro chachikulu ndi 36 km/h.-1 ndi kupanikizika kwa 9,1 x 105 Pa, pomwe kupanikizika mu chitoliro chaching'ono ndi 2.105 Pa, ndiye kuti liwiro la madzi mu chitoliro chaching'ono ndi…. (kuchuluka kwa madzi = 103 kg.m-3)
A. 10 ms-1
B. 20 ms-1
C. 30 ms-1
D. 40 ms-1
E. 50 ms-1
Zokambirana
Amadziwika kuti:
Kupanikizika kwa madzi m'mapaipi akuluakulu (p)1) = 9,1 x 105 Pascal = Ma Pascal 910.000
Kupanikizika kwa madzi m'mapaipi ang'onoang'ono (p)2) = 2 x 105 Pascal = Ma Pascal 200.000
Liwiro la madzi m'mapaipi akuluakulu (v)1) = 36 km/h = 36(1000)/(3600) = 36000/3600 =10 m/s
Kutalika kwa chitoliro chachikulu (h)1) = -4 mamita
Kutalika kwa chitoliro chaching'ono (h)2) = mamita 0
Kuthamanga chifukwa cha mphamvu yokoka (g) = 10 ms-2
Kuchuluka kwa madzi (ρ) = 1000 kg.m-3
Anafunsa kuti: Liwiro la madzi mu chitoliro chaching'ono (v)2)
Yankho:
Liwiro la madzi mu chitoliro chaching'ono (v)2) amawerengedwa pogwiritsa ntchito equation ya Bernoulli:
910.000 + ½ (1000)(102) + (1000) (10) (0) = 200.000 + ½ (1000) (v22) + (1000)(10)(-4)
910.000 + 50.000 + 0 = 200.000 + 500 v22 - 40.000
960.000 = 160.000 + 500 v22
800.000 = 500 v22
800.000 / 500 = v22
1600 = v22
v2 = √1600
v2 = 40 m/s
Yankho lolondola ndi D.
Gwero la funso:
Mafunso a National Examination Physics a Senior High School/Vocational High School
