Zitsanzo za mafunso okhudza Mafunde a Mechanical

Zitsanzo 13 za Mafunde a Makina

1. Magawo osiyanasiyana mafunde opingasa

Samalani ndi chithunzicho mafunde sinusoidal yotsatirayi!

Ngati kutalika kwa mafunde a sinusoid pamwambapa ndi 80 cm, ndiye kuti mfundo yomwe ili ndi kusiyana kwa gawo la ¾ ndi…

A. P ndi Q

B. P ndi R

C. P ndi S

D. Q ndi S

E. R ndi S

Zokambirana

PQ = 3/4 kutalika kwa mtunda

PR = 1 1/2 = 1,5 ma wavelength

PS = mafunde awiri

QS = 1 1/4 = 1,25 mafunde a mlengalenga

RS = 1/2 kutalika kwa mtunda

Yankho lolondola ndi A.

2. Mapaipi otseguka ndi otsekedwa a ziwalo

Mapaipi awiri a ziwalo amaperekedwa, limodzi lotseguka ndi lina lotsekedwa, lililonse lili ndi kutalika kofanana. Ngati liwiro la phokoso mumlengalenga ndi 340 m/s, ndiye kuti chiŵerengero cha ma frequency a overtone a mapaipi awiri otseguka a ziwalo ndi ma frequency a overtone a mapaipi awiri otsekedwa a ziwalo ndi…

Zokambirana

Ndizodziwika kuti:

Kutalika kwa chitoliro chotseguka ndi chotsekedwa cha ziwalo ndi chimodzimodzi.

Liwiro la phokoso mumlengalenga (v) = 340 m/s

Anafunsa kuti:

Yankho: Kuyerekeza kwa fmafupipafupi achiwiri a overtone (f)₃) mapaipi otseguka ndi otsekedwa a ziwalo

Chitoliro chotseguka cha ziwalo

Chitoliro chotseguka cha ziwalo kapena chubu chotseguka ndi chubu chomwe chili ndi malekezero onse awiri otseguka monga momwe zilili pachithunzi cha mbali.

Chithunzi chomwe chili kumanja chili ndi graph ya mafunde a mawu mu chitoliro chotseguka cha ziwalo, komwe ma node akuyimira kuchuluka kwa mpweya ndipo ma antinode akuyimira kuthamanga kwa mpweya.

Kamvekedwe koyambira (f)₁) = v / 2L = 340/2L = 170/L

Kamvekedwe kachiwiri (f)₃) = 3 f₁ = 3 (170/L) = 510/L

Chitoliro chotsekedwa cha ziwalo

Chitoliro chotsekedwa cha ziwalo, kapena chubu chotsekedwa, ndi chubu chokhala ndi mbali imodzi yotseguka ndi inayo yotsekedwa, monga momwe chithunzi chili pansipa chikusonyezera. Ngati mbali zonse ziwiri za chubucho zatsekedwa, chubucho sichingagwiritsidwe ntchito.

Chithunzi chomwe chili kumanja chili ndi graph ya mafunde a mawu mu chitoliro chotsekedwa cha ziwalo, komwe ma node akuyimira kuchuluka kwa mpweya ndipo ma antinode akuyimira kuthamanga kwa mpweya.

Kamvekedwe koyambira (f)₁) = v / 4L = 340/4L = 85/L

Kamvekedwe kachiwiri (f)₃) = 3 f₁ = 3 (85/L) = 255/L

Kuyerekeza kwa fmafupipafupi achiwiri a overtone (f)₃) mapaipi otseguka ndi otsekedwa a ziwalo

510/L: 255/L

510: 255

2: 1

3. Mlingo wa mphamvu ya mafunde a phokoso

Gwero la mafunde a mawu okhala ndi mphamvu ya 12,56 W limatulutsa mafunde m'malo ozungulira mofanana. Mphamvu ya malire a mawu ndi 10^-12 Wm^-2Mlingo wa mphamvu ya mafunde a radiation pamtunda wa mamita 10 kuchokera ku gwero lake ndi…

Zokambirana

Ndizodziwika kuti:

Mphamvu = 12,56 Watt

Mphamvu ya phokoso (I)_o= = 10^-12 Wm^-2

Mtunda (r) = mamita 10

Anafunsa kuti: Mlingo wa mphamvu (TI)

Yankho:

Fomula ya ubale pakati pa mphamvu (P), mphamvu (I) ndi mtunda (r):

Mlingo wa mphamvu (TI):

4. Mphamvu ya mawu

Dongosolo la zokuzira mawu limatulutsa mphamvu ya 36 Hz ya mawu.π ma watts ndi mphamvu ya 80 dB ikamveka patali x kuchokera pa cholankhulira. (I_o = 10^-12 watt.m^-2Mtengo woyenera wa x ndi…

A. 100 m

B. 160 m

C. 175 m

D. 225 m

E. 300 m

Zokambirana

Amadziwika kuti:

Mphamvu (P) = 36π Watt

Mlingo wa mphamvu (TI) = 80 dB

Mtunda = x

Malire a kumva kwa anthu (I)_o= = 10^-12 Watt.m^-2

Anafunsa kuti: Mtengo wa x

Yankho:

Fomula ya ubale pakati pa mphamvu (P), mphamvu (I) ndi mtunda (x):

Choyamba werengerani mphamvu ya mawu pa mtunda x:

Mphamvu ya mawu:

Werengerani mtengo wa x:

Yankho lolondola ndi E.

5. Mafunde Oyenda

2015/2016 SMA/MA Fiziki Funso la Mayeso a Dziko Lonse Nambala 24

Chiyerekezo cha mafunde oyendayenda chomwe chafotokozedwa mu International System of Units (SI) ndi y = 0,2 sin (0,2)πx-20πt)

Kuchokera m'mawu otsatirawa:

(1) Liwiro la kufalikira kwa mafunde 100 ms^-1

(2) Pa x = 0 ndipo t = 0 kupotoka kwa mafunde = 0

(3) Mafunde othamanga 20 Hz

(4) Kukula kwa mafunde 2 cm

Ndi iti yolondola?

A. (1) ndi (2)

B. (1) ndi (3)

C. (1) ndi (4)

D. (2) ndi (4)

E. (2) ndi (3)

Zokambirana

Mitundu itatu ya ma equation a mafunde:

y = A sin (ωt – kx) ——> 1

ω = 2π / T ndi k = 2π / λ

y = tchimo (2π/T) t – (2π/λ) x

y = A sin 2π (t/T – x/λ) ——-> 2

y = A sin 2π (ft – x/λ) ——-> 2

T = 1/f ndi λ = v/f

y = A sin 2π (ft – f(x/v))

y = A sin 2πf (t – x/v) ——-> 3

Equation ya mafunde oyendayenda mu funso lomwe lili pamwambapa ndi yofanana ndi fomu 2:

y = 0,2 tchimo (0,2πx-20πt)

y = 0,2 tchimo π (0,2x-20t)

y = 0,2 tchimo 2π (0,1x-10t)

y = 0,2 tchimo 2π (x/10 -10t)

y = A sin 2π (ft – x/λ)

A = kukula kwake = mamita 0,2 = 0,2 (100 cm) = masentimita 20

f = pafupipafupi = masekondi 10^-1 = 10 Hertz

λ = kutalika kwa mtunda = mamita 10

v = liwiro la kufalikira kwa mafunde = f λ = (masekondi 10^-1)(10 m) = 100 ms^-1

Yankho lolondola ndi A.

6.  Zotsatira za Doppler

Ambulansi ikuyenda pa liwiro la 72 km/h.^-1 pamene akuimba siren yokhala ndi ma frequency a 1500 Hz. Woyendetsa njinga yamoto akuyenda pa liwiro la 20 m/s^-1 mbali yosiyana ndi ambulansi. Ngati liwiro la phokoso mumlengalenga ndi 340 ms^-1, ndiye kuti chiŵerengero cha ma frequency omwe woyendetsa njinga yamoto amamva akamayandikira ndi kuchoka pa ambulansi ndi...

A. 25: 36

B. 36: 49

C. 64: 81

D. 81: 64

E. 100: 61

Zokambirana

Malamulo osainira:

v nthawi zonse imakhala yabwino

v_p zabwino ngati womverayo ayandikira komwe mawu akuchokera

v_p zoipa ngati womverayo achoka pa gwero la mawu

v_s zabwino ngati gwero la mawu likuyang'ana kutali ndi womvera

v_s zoipa ngati gwero la mawu likuyandikira womvera

v_p = 0 ngati womverayo ali chete

v_s = 0 ngati gwero la mawu likadalipo

Amadziwika kuti:

Mafupipafupi a gwero la mawu (f) = 1500 Hz

Liwiro la womvera (v)_p) = 20 m / s

Liwiro la gwero la mawu (v)_s) = 72 Km / kupanikizana = 72 (mamita 1000) / masekondi 3600 = 72.000/mamita 3600/sekondi = 20 m/s

Liwiro la phokoso (v) = 340 m/s

Anafunsa kuti: PKuyerekeza ma frequency omwe amamveka ndi oyendetsa njinga zamoto akamayandikira ndi kuchoka pa ambulansi

Yankho:

Fomula ya zotsatira za Doppler:

Kuchuluka kwa mawu omwe munthu woyendetsa njinga yamoto amamva akamayandikira ambulansi

Onse awiri anali kupita mbali zosiyana kotero njinga yamoto itafika pafupi ndi ambulansi, onse awiri anayandikirana. v_p zabwino ngati womverayo ayandikira gwero la mawu ndi v_s zoipa ngati gwero la mawu likuyandikira womvera.

Kuchuluka kwa anthu okwera njinga zamoto kumamveka akachoka pa ambulansi

Onse awiri anali kupita mbali zosiyana kotero kuti njinga yamoto ikachoka pa ambulansi, iwo anachoka wina ndi mnzake. v_p zoipa ngati womverayo achoka pa gwero la mawu ndi v_s zabwino ngati gwero la mawu likuyang'ana kutali ndi womvera.

PKuyerekeza ma frequency omwe amamveka ndi oyendetsa njinga zamoto akamayandikira ndi kuchoka pa ambulansi.

Yankho lolondola ndi D.

Mphamvu ya Phokoso

7. Dziwani zambiri!

Ngati mfundo P ndi gwero la mawu lomwe limatuluka mbali zonse, ndiye kuti chiŵerengero cha mphamvu ya mawu pa mfundo S, R, ndi Q motsatana ndi...

A. 16: 25: 100

B. 16 : 50 : 200

C. 32 : 50 : 100

D. 36 : 25 : 100

E. 72 : 25 : 200

Zokambirana

Amadziwika kuti:

Mtunda wa mfundo Q kuchokera ku gwero la mawu (r)_Q) = mamita 3

Mtunda wa mfundo R kuchokera ku gwero la mawu (r_R) = mamita 6

Mtunda wa mfundo S kuchokera ku gwero la mawu (r)_S) = mamita 5

Mphamvu ya mawu pa mfundo Q = I_Q

Mphamvu ya mawu pa mfundo R = I_R

Mphamvu ya mawu pa mfundo S = I_S

Anafunsa kuti: Pkuyerekeza mphamvu ya mawu pa mfundo S, R, ndi Q (I_S : Ine_R : Ine_Q)

Yankho:

Mphamvu ya mawu pa mfundo S:

Mphamvu ya mawu pa mfundo R:

Mphamvu ya mawu pa mfundo S:

PKuyerekeza mphamvu ya mawu pa mfundo S, R, ndi Q:

Yankho lolondola ndi D.

8. Mafunde a mawu amafalikira kuchokera ku gwero lawo mbali zonse mofanana. Mfundo A ili patali ndi P kuchokera ku gwero la mawu, mfundo B ili patali ndi 2P kuchokera ku gwero la mawu, ndipo mfundo C ili patali ndi 4P kuchokera ku gwero la mawu. Chiŵerengero cha mphamvu ya mawu yomwe A, B, ndi C amalandira ndi…

A. 16: 4: 1

B. 4 : 2 : 1

C. 4 : 1 : 16

D. 1 : 2 : 4

E. 1 : 4 : 16

Zokambirana

Amadziwika kuti:

Mtunda wa mfundo A kuchokera ku gwero la mawu (r)_A) = P

Mtunda wa mfundo B kuchokera ku gwero la mawu (r)_B) = 2P

Mtunda wa mfundo C kuchokera ku gwero la mawu (r)_C) = 4P

Mphamvu ya mawu pa mfundo A = I_A

Mphamvu ya mawu pa mfundo B = I_B

Mphamvu ya mawu pa mfundo C = I_C

Anafunsa kuti: Pkuyerekeza mphamvu ya mawu pa mfundo A, B, ndi C (I_A : Ine_B : Ine_C)

Yankho:

Mphamvu ya mawu pa mfundo A:

Mphamvu ya mawu pa mfundo B:

Mphamvu ya mawu pa mfundo C:

PKuyerekeza mphamvu ya mawu pa mfundo A, B, ndi C:

Yankho lolondola ndi A.

9. Zotsatira za Doppler

Chithunzi chotsatirachi chikuwonetsa galimoto ya apolisi ikuthamangitsa chigawenga choyendetsa galimoto:

Galimoto ya apolisi ikuimba siren yokhala ndi pafupipafupi 930 Hz ikuthamangitsa njinga yamoto ya chigawenga chothawa pa liwiro la 72 km/h^-1Galimoto ya apolisi inathamanga kufika pa 108 km/h^-1 kuti athane ndi chigawengacho. Ngati liwiro la phokoso mlengalenga ndi 340 ms^-1, ndiye kuti pafupipafupi phokoso la siren lomwe woyendetsa njinga yamoto amamva ndi...

A. 850 Hz

B. 900 Hz

C. 960 Hz

D. 1.020 Hz

E. 1.200 Hz

Zokambirana

Malamulo osainira:

v nthawi zonse imakhala yabwino

v_p zabwino ngati womverayo ayandikira komwe mawu akuchokera

v_p zoipa ngati womverayo achoka pa gwero la mawu

v_s zabwino ngati gwero la mawu likuyang'ana kutali ndi womvera

v_s zoipa ngati gwero la mawu likuyandikira womvera

v_p = 0 ngati womverayo ali chete

v_s = 0 ngati gwero la mawu likadalipo

Amadziwika kuti:

Kuchuluka kwa magwero a mawu (f) = 930 Hz

Liwiro la womvera (v)_p) = 72 km/h^-1 = 72 (mamita 1000) / 3600 (masekondi) = 72.000/3600 mamita/sekondi = 20 m/s = -20 ms^-1 (zoipa chifukwa zigawenga zimapewa apolisi)

Liwiro la gwero la mawu (v)_s) = 108 km/h^-1 = 108 (mamita 1000) / 3600 (masekondi) = 108.000/3600 mamita/sekondi = 30 m/s = -30 ms^-1 (zoipa chifukwa apolisi adapita kwa wachifwamba)

Liwiro la mawu (v) = 340 ms^-1

Anafunsa kuti: Kuchuluka kwa mawu omwe omvera amamva (f')

Yankho:

Fomula ya zotsatira za Doppler:

Yankho lolondola ndi C.

Mlingo wa Mphamvu ya Phokoso

10. Mu holo, ophunzira 100 akuphunzira kuimba. Ngati mulingo wa mphamvu ya mawu wa wophunzira m'modzi poimba ndi 40 dB (poganiza kuti ndi wofanana kwa mwana aliyense), ndiye kuti mphamvu ya mawu yomwe imapangidwa mu holo ndi… (Ine)._o = 10^-12 Wm^-2)

A. 10^-4 Wm^-2

B. 10^-5 Wm^-2

C. 10^-6 Wm^-2

D. 10^-7 Wm^-2

10^-8 Wm^-2

Zokambirana

Amadziwika kuti:

Mlingo wa mphamvu ya wophunzira m'modzi (T)_I) = 40 dB

Mphamvu ya kumva kwa anthu (I)_o) = 10^-12 W / m²

Chiwerengero cha ophunzira (x) = 100

Anafunsa kuti: Mphamvu ya phokoso la ophunzira 100

Yankho:

Mphamvu ya phokoso la wophunzira m'modzi:

Mphamvu ya phokoso la wophunzira m'modzi:

I_x = (x)(I)

I_x = (100)(10^-8) = (10)²)(10)^-8)

I_x = 10^-6 W / m²

Yankho lolondola ndi C.

11. Mphamvu ya mawu a makina 100 ofanana ndi 10^-7 Watt.m^-2Ngati ine_o = 10^-12 Watt.m^-2, ndiye kuti mphamvu ya mawu ya makina ndi….

A. 70 dB

B. 60 dB

C. 50 dB

D. 40 dB

E. 30 dB

Zokambirana

Amadziwika kuti:

Mphamvu ya mawu a makina 100 (I)_x) = 10^-7 Watt.m^-2

Mphamvu ya kumva kwa anthu (I)_o) = 10^-12 W / m²

Chiwerengero cha makina (x) = 100 = 10²

Anafunsa kuti: Mphamvu ya phokoso la makina (TI)

Yankho:

Mphamvu ya phokoso la makina amodzi:

I_x = (x)(I)

10^-7 = (10)²)(I)

Ine = 10^-7 / 10² = (10)^-7)(10)^-2= = 10^-9

Mphamvu ya phokoso la makina (TI):

Yankho lolondola ndi E.

12. Katundu wa mafunde ndi awa:
(1) sizingafalikire mu malo opanda kanthu
(2) imafalikira molunjika m'ma media osiyanasiyana
(3) kusinkhasinkha
(4) kukhala ndi diffraction
(5) kusokonezedwa

Kuchokera ku makhalidwe a mafunde omwe ali pamwambapa, zomwe zikugwirizana ndi makhalidwe a mafunde a kuwala ndi...

A. (1) ndi (2) zokha
B. (3) ndi (4) zokha
C. (2), (3), ndi (4)
D. (3), (4), ndi (5)
E. (1), (3), (4), ndi (5)

Zokambirana

(1) Mafunde owala ndi mafunde amagetsi omwe safuna njira yofalitsira. Chifukwa safuna njira yofalitsira, mafunde amagetsi amatha kufalikira mu vacuum.
(2) Pamene mafunde a kuwala omwe akufalikira mu sing'anga alowa mu sing'anga yatsopano, mafunde a kuwala nawonso amakumana ndi kutembenuka. Kusuntha kwa kuwala ndi kupindika kwa njira yofalikira kwa mafunde a kuwala. Kusuntha kumachitika chifukwa cha kusiyana kwa liwiro la mafunde a kuwala mu sing'anga iliyonse yosiyana.
(3) Kupatula kuwona kugwedezeka, mafunde a kuwala amawonanso kugwedezeka. Kuwunikira kwa kuwala ndi galasi lathyathyathya ndi chitsanzo chimodzi cha momwe kuwala kumawunikira. Kuwunikira kwa kuwala ndi galasi lathyathyathya kumapangitsa kuti magalasi athyathyathya agwiritsidwe ntchito ngati zida zodzoladzola.
(4) Kusinthasintha kwa mafunde sikuti kumachitika kokha ndi mafunde amagetsi monga mafunde a kuwala, komanso kumachitika ndi mafunde amakina monga mafunde amadzi ndi mafunde amawu.
(5) Kupatula kukhudzidwa ndi mafunde amagetsi monga mafunde a kuwala, kusokonezeka kumakhudzidwanso ndi mafunde amakina monga mafunde amadzi, mafunde a chingwe kapena mafunde amawu.
Yankho lolondola ndi D.

13. Samalani ndi makhalidwe otsatirawa a mafunde!
(1) kukhala ndi diffraction
(2) kusinkhasinkha
(3) sizingafalikire mu malo opanda kanthu
(4) akhoza kukhala ndi polarization
(5) imayenda molunjika ikadutsa m'njira ziwiri zosiyana
Kuchokera ku makhalidwe a mafunde omwe ali pamwambapa, omwe akugwirizana ndi makhalidwe a mafunde a phokoso ndi...

A. (1), (2) ndi (3)
B. (1), (2) ndi (4)
C. (1), (3) ndi (4)
D. (2), (3) ndi (4)
E. (3), (4) ndi (5)

Zokambirana
(1) Kusinthasintha kwa mafunde sikuti kumangochitika ndi mafunde amagetsi monga mafunde a kuwala, komanso kumachitikira ndi mafunde amakina monga mafunde a phokoso.
(2) Kuwunikira kapena kugwedezeka kumachitika ndi mafunde amagetsi monga mafunde a kuwala ndi mafunde amakaniko monga mafunde a phokoso kapena mafunde amadzi. Chitsanzo cha chochitika cha kuwunikira kwa mafunde a phokoso ndi echo.
(3) Mafunde amawu ndi mafunde amawu. Mafunde amawu ndi mafunde omwe amafunikira njira yofalitsira kuti afalikire. Ngati palibe njira yofalitsira, monga mu vacuum, ndiye kuti mafunde amawu sangafalikire.

(4) Polarization imachitika ndi mafunde opingasa monga mafunde a chingwe, mafunde a pamwamba pa madzi ndi mafunde amagetsi monga mafunde owala. Mafunde a phokoso ndi mafunde a longitudinal ndipo motero sangakumane ndi polarization.
(5) Pofalikira kuchokera ku chinthu chimodzi kupita ku chinthu china, mafunde amamveka ngati akugwedezeka kapena kusintha kwa njira yofalikira. Kugwedezeka kumachitika pamene mafunde ayamba kulowa mu chinthu china.
Yankho lolondola ndi A.

 

 

Gwero la funso:

Mafunso a National Examination Physics a Senior High School/Vocational High School