Imibuzo eyisibonelo ngomsebenzi namandla

Izibonelo eziyi-16 zemibuzo yomsebenzi kanye namandla

Ithiyori Amandla E-Work-Kinetic

1. Amandla angaguquki angu-60 N asebenza imizuzwana eyi-12 entweni enesisindo esingu-10 kg. Into

inesivinini sokuqala esingu-6 m/sec ohlangothini olufanayo namandla.

(1) Umsebenzi owenziwe kule nto ungama-joule angu-30.240

(2) Amandla okugcina e-kinetic ento angama-30.240 joules.

(3) Amandla akhiqizwayo angama-watts angu-2.520

(4) Ukwanda kwamandla e-kinetic ento kungama-joules ayi-180.

Isitatimende esinembile sithi…

A. 1, 2 kanye no-3

B. 1 no-3

C. 1 no-4

D. 4 kuphela

E. konke kulungile

Ingxoxo

Kuyaziwa ukuthi:

Amandla (F) = 60 N

Isikhawu sesikhathi (t) = imizuzwana eyi-12

Isisindo sento (m) = 10 kg

Ijubane lokuqala (v _o ) = 6 m/s

Umbuzo: Yisiphi isitatimende esinembile?

Impendulo:

Ukusheshisa into:

∑ F = ma

60 = 10 a

a = 60 / 10 = 6 m/s ²

Isivinini sokugcina:

v _t = vo _o + at

v _t = 6 + (6)(12)

v _t = 6 + 72

v _t = 78 m/s

Ibanga elihanjiwe ngemizuzwana eyi-12:

s = vot ₊ 1/2 ku- ²

s = (6)(12) + 1/2 (6)(12) ²

s = 72 + (3)(144)

s = 72 + 432

s = amamitha angu-504

(1) Umsebenzi usuqedile

W = F s = (60)(504) = 30.240 amaJoules

(2) Amandla okugcina e-kinetic ento

EK = 1/2 mv _t ² = 1/2 (10) (78) ² = (5) (6084) = 30.420 Joules

(3) Amandla akhiqizwayo

P = W / t = 30.240 / 12 = 2.520 amaJoules/isekhondi

(4) Ukwanda kwamandla e-kinetic

ΔEK = 1/2 mv _t ² – 1/2 mv _o ² = 1/2 m (v _t ² – v _o ² ) = 1/2 (10)(78 ² – 6 ² ) = 5 (6084 –36) = 5 (6048)

ΔEK = 30.240 amaJoules

Impendulo efanele ingu-B.

2. Idatha ngokushintsha kwejubane lento ehamba emgqeni oqondile ivezwa kanje. Umsebenzi omkhulu kakhulu wenziwa yinombolo yento….

A. 1

B. 2

C. 3

D. 4

E. 5

Ingxoxo

Ithiyori yamandla e-work-kinetic:

Umsebenzi ophelele = ushintsho kumandla e-kinetic

Ingqikithi = ½ m (v _{t 2} ^– v _o ² )

Amabhizinisi amakhulu yilawa:

W ₁ = ½ (8)(4 ² – 2 ² ) = (4)(16 – 4) = (4)(12) = 48 Ama-Joules

W ₂ = ½ (8)(5 ² –3 ² ) = (4)(25 – 9) = (4)(16) = 64 Ama-Joules

W ₃ = ½ (10)(6 ² – 5 ² ) = (5)(36 – 25) = (5)(11) = 55 Ama-Joules

W ₄ = ½ (10)(4 ² – 0 ² ) = (5)(16 – 0) = (5)(16) = 80 Ama-Joules

W ₅ = ½ (20)(3 ² – 3 ² ) = (10)(9 – 9) = (10)(0) = 0 Ama-Joules

Impendulo efanele ngu-D.

3. U-Odi ushayela imoto enesisindo esingu-4000 kg emgwaqweni oqondile ngesivinini esingu-25 m/s. Ebona ukuminyana kwezimoto kude, ubhuleka imoto ukuze isivinini semoto sehle njalo sibe ngu-15 m/s. Umsebenzi owenziwa yibutho lokubhuleka….

A. 200 kJ

B. 300 kJ

C. 400 kJ

D. 700 kJ

E. 800 kJ

Ingxoxo

Kuyaziwa ukuthi :

Isisindo semoto (m) = 4000 kg

Isivinini sokuqala semoto (v _o ) = 25 m/s

Isivinini sokugcina semoto (v _t ) = 15 m/s

Umbuzo : Umsebenzi (W) emotweni?

Impendulo :

Ithiyori yamandla e-work-kinetic:

Ingqikithi = ½ m (v _t ² – vo ₂ ⁾ = ½(4000)(15 ² -25 ² ) = (2000)(225-625) = (2000)(-400) = -800.000 AmaJoules = -800 amakhilogremu AmaJoules_.

Impendulo efanele ngu-E.

4. Ibhola elinesisindo esingu-0,1 kg liphonswa ngokuvundlile ngesivinini esingama-6 m/s ukusuka ophahleni lwesakhiwo esingamamitha ama-5 ukuphakama. Uma ukusheshisa okubangelwa amandla adonsela phansi kuleyo ndawo kungu-10 m/s ² , khona-ke amandla e-kinetic ebhola eliphakeme ngamamitha ama-2….

A. 6,8 J

B. 4,8 J

C. 3,8 J

D. 3 J

E. 2 J

Ingxoxo

Kuyaziwa ukuthi :

IMisa (m) = 0,1 kg

Ukushintsha kokuphakama (h) = 5 m – 2 m = 3 amamitha

Ukusheshisa ngenxa yamandla adonsela phansi (g) = 10 m/s ²

Umbuzo : amandla e-kinetic (EK) ekuphakameni kwamamitha amabili?

Impendulo :

Indlela ibhola elihamba ngayo injengoba kuboniswe esithombeni esingezansi.

Ukunyakaza okufana nokwe-parabolic njengoba kuboniswe esithombeni esingenhla kuyinhlanganisela yokunyakaza okubili okungahlaziywa ngokwehlukana, lapho ukunyakaza ohlangothini oluvundlile kusesimweni sokunyakaza okuqondile okuvamile kanti ukunyakaza ohlangothini oluqondile kusesimweni sokunyakaza kokuwa kwamahhala.

Le nkinga ixazululwa kusetshenziswa umthetho wokulondolozwa kwamandla omshini, ngakho-ke sicabangela ukunyakaza okuqonde ngqo kuphela ngesimo sokunyakaza kokuwa kwamahhala.

Yonke into ehamba ngokuwa okukhululekile ayinaso isivinini sokuqala (v _o = 0) ngakho-ke amandla okuqala e-kinetic ento ayi-zero (EK = ½ mv ² = 0). Ngakolunye uhlangothi, into iqala ukuhamba isuka ekuphakameni kwamamitha ama-5 ngaphezu komhlabathi ngakho into inamandla adonsela phansi. Ngakho-ke amandla okuqala omshini ebhola amandla adonsela phansi. Lapho ibhola liqala ukuhamba phansi, amandla adonsela phansi ebhola ashintsha abe amandla e-kinetic. Amandla adonsela phansi ashintsha abe amandla e-kinetic lapho ibhola lisuka ekuphakameni kwamamitha ama-5 ngaphezu komhlabathi liye ekuphakameni kwamamitha ama-2 ngaphezu komhlabathi: EP = mgh = (0,1)(10)(3) = 3 Joules. Uma ibhola lisekuphakameni kwamamitha ama-2 ngaphezu komhlabathi, amandla e-kinetic ebhola angama-3 Joules.

Impendulo efanele ngu-D.

5. Imoto enesisindo sethani eli-1 iqala lapho iphumule. Ngemva kwesikhashana, ijubane layo lingu-5 m/s ^-1 . Inani lomsebenzi owenziwe yinjini yemoto...

A. 1000 Joule

B. 2.500 Joule

C. 5.000 Joule

D. 12.500 Joule

E. 25.000 AmaJoule

Ingxoxo

Kuyaziwa ukuthi :

Isisindo (m) = 1 ithani = 1000 kg

Ijubane lokuqala (v _o ) = 0 (imoto iqala kusukela ekuphumuleni)

Isivinini sokugcina (v _t ) = 5 m/s

Umbuzo : Ungakanani umsebenzi (W) owenziwa yinjini yemoto?

Impendulo :

Ithiyori yamandla e-work-kinetic:

Ingqikithi = ½ m (v _{t 2} ^– v _o ² )

Umsebenzi owenziwa yinjini yemoto umi kanje:

Ingqikithi = ½ (1000)(5 ² – 0 ² ) = (500)(25 – 0) = (500)(25) = 12.500 _amaJoules

Impendulo efanele ngu-D.

6. Ibhola elinesisindo esingamagremu angu-500 liphonswa phezulu lisuka phansi ngesivinini sokuqala esingu-10 ms ^-2 . Uma u-g = 10 ms ^-2 , khona-ke umsebenzi owenziwa amandla adonsela phansi ebhola uma lifika ekuphakameni kwalo okuphezulu...

A. 2,5 J

B. 5,0 J

C. 25 J

D. 50 J

E. 500 J

Ingxoxo

Unganaki ukumelana nomoya.

Kuyaziwa ukuthi :

Isisindo sebhola (m) = amagremu ayi-500 = 0,5 kg

Ijubane lokuqala (v _o ) = 10 m/s ²

Ijubane lokugcina (v _t ) = 0. Ekuphakameni okuphezulu, into iphumule isikhashana ngaphambi kokubuyela emuva.

Ukusheshisa ngenxa yamandla adonsela phansi (g) = 10 m/s ²

Okufunwayo : Umsebenzi (W) owenziwe ngamandla adonsela phansi ebhola

Impendulo :

Ithiyori yamandla e-work-kinetic :

I-work-kinetic energy theorem ithi umsebenzi noma umzamo ophelele owenziwe ngamandla aphumayo entweni ulingana noshintsho kumandla e-kinetic ento. Ifomula ye-work-kinetic energy theorem yile:

W _inani = ΔEK = EK _t – EK _o

Ingqikithi = ½ mv _t ² – ½ mv o _{2 =} ½ m (v _t ² – _vo ^{2 )}

Imininingwane:

EK _t = amandla okugcina e-kinetic, EK _o = amandla okuqala e-kinetic, m = isisindo sento, v _t = ijubane lokugcina lento, v _o = ijubane lokuqala lento.

Umzamo ophelele :

Umsebenzi owenziwe ngamandla adonsela phansi ebhola kusukela ngesikhathi ibhola liphonswa kuze kube yilapho ibhola lifinyelela ukuphakama kwalo okuphezulu yilokhu:

Ingqikithi = ½ m (v _t ² _– vo ₂ ⁾ = ½ (0,5)(0 ² – 10 ² )

_{Ingqikithi engu-} W = (0,25)(-100) = -25 AmaJoules

Isibonakaliso esingesihle sibonisa ukuthi indlela ibhola elihamba ngayo iphambene nendlela ibhola elihamba ngayo. Indlela ibhola elihamba ngayo iphezulu, kanti indlela ibhola elihamba ngayo iphansi. Amandla adonsela phansi enza umsebenzi ongemuhle ebholeni, okusho ukuthi umsebenzi owenziwa amandla adonsela phansi wandisa amandla adonsela phansi ebhola futhi wehlisa amandla alo e-kinetic. Amandla adonsela phansi enza umsebenzi omuhle uma indlela ibhola elihamba ngayo ifana nendlela ibhola elihamba ngayo (ibhola liyehla).

Impendulo efanele ngu-C.

7. Ibhola elinesisindo esingu-1 kg liyawa ngaphandle kwesivinini sokuqala lisuka phezulu kwesakhiwo lidlule efasiteleni A esitezi esiphezulu liye efasiteleni B esitezi esingezansi ngomehluko wokuphakama ongu-2,5 m (g = 10 ms ^-2 ). Ungakanani umsebenzi owenziwayo ukuhambisa ibhola lisuka efasiteleni A liye efasiteleni B?

A. 5 Joule

B. 15 Joule

C. 20 Joule

D. 25 Joule

E. 50 AmaJoule

Ingxoxo

Kuyaziwa ukuthi :

Isisindo sebhola (m) = 1 kg

Ijubane lokuqala (v _o ) = 0 m/s

Ukuphakama (h) = amamitha ayi-2,5

Ukusheshisa ngenxa yamandla adonsela phansi (g) = 10 m/s ²

Umbuzo : Umzamo ophelele ngesikhathi sokunyakaza kwebhola

Impendulo :

Ijubane lokugcina lebhola (v _t )

Ibhola liwela ngaphandle kwejubane lokuqala, ngakho-ke ukunyakaza kwebhola kuwela ngokukhululekile. Okokuqala, bala ijubane lokugcina lebhola usebenzisa ifomula yokuwa ngokukhululekile. Njengoba kunikezwe ukusheshisa okubangelwa amandla adonsela phansi (g) = 10 m/s ² , ushintsho ekuphakameni kwebhola (h) = 2,5 amamitha, kanye nejubane lokugcina (v _t ) liyabuzwa, ngakho-ke sebenzisa ifomula v _t ² = 2 gh

v _t ² = 2 gh = 2(10)(2,5) = 2(25)

v _t = √2(25) = 5√2

Ngakho ijubane lokugcina lebhola lingu-5√2 m/s

Umsebenzi ophelele = ushintsho kumandla e-kinetic

Ingqikithi = _ΔEK = ½ m (v _t ² – vo ₂ ⁾ = ½ (1){(5√2) ² – 0 ² }

Ingqikithi = ½ (25)(2) = 25 _AmaJoules

Impendulo efanele ngu-D.

8. Into enesisindo esingu-2 kg iqala ukuhamba ngesivinini esingu-72 km/h ^-1 . Ngemva kokuhamba ngamamitha angu-400, isivinini sento siba ngu-144 km/h ^-1 kanye (g = 10 m/s ^-2 ). Umsebenzi ophelele owenziwe yinto ngaleso sikhathi...

A. 20 J

B. 60 J

C. 1.200 J

D. 2.000 J

E. 2.400 J

Ingxoxo

Kuyaziwa ukuthi :

Isisindo sento (m) = 2 kg

Ijubane lokuqala (v _o ) = 72 km/h = 20 m/s

Ijubane lokugcina (v _t ) = 144 km/h = 40 m/s

Ibanga elihanjiwe = amamitha ayi-400

Ukusheshisa ngenxa yamandla adonsela phansi (g) = 10 m/s ²

Kubuziwe : Umzamo ophelele

Impendulo :

Umsebenzi ophelele = ushintsho kumandla e-kinetic

Ingqikithi = _ΔEK = ½ m (v _t ² – vo ₂ ⁾ = ½ (2)(40 ² – 20 ² }

Ingqikithi _engu- W = ½ (2)(1600 - 400) = 1200 amaJoules

Impendulo efanele ngu-C.

9. Into enesisindo esingu-2 kg ihamba endaweni ebushelelezi ngesivinini esingu-2 m/s ^–1 . Uma kwenziwa ama-joule angu-21 ento, isivinini sento sizoshintsha sibe…

A. 1 ms ^–1

B. 2 ms ^–1

C. 3 ms ^–1

D. 5 ms ^–1

E. 17 ms ^–1

Ingxoxo

Kuyaziwa ukuthi:

IMisa (m) = 2 kg

Ijubane lokuqala (v _o ) = 2 m/s

Umsebenzi (W) = ama-Joules angu-21

Umbuzo: Ijubane lokugcina (v _t )

Impendulo:

Ithiyori yamandla okusebenza ne-kinetic ithi umsebenzi ophelele owenziwe entweni ulingana noshintsho emandleni e-kinetic ento. Ngokwezibalo:

Ingqikithi = ΔEK

Ingqikithi = 1/2 mv _t ² -1/2 mv _o ²

Ingqikithi = 1/2 m (v _t ² – v _o ² )

21 = 1/2 (2) (v _t ² – 2 ² )

21 = (v _t ² – 2 ² )

21 = v _t ² – 4

v _t ² = 21 + 4 = 25

v _t = √25

v _t = 5 m/s

Impendulo efanele ngu-D.

10. Ibhola elinesisindo esingamagremu angu-500 liphonswa phezulu lisuka phansi ngesivinini sokuqala esingu-10 ms ^-2 . Uma u-g = 10 ms ^-2 , khona-ke umsebenzi owenziwa amandla adonsela phansi ebhola uma lifika ekuphakameni kwalo okuphezulu...

A. 2,5 J
B. 5,0 J
C. 25 J
D. 50 J
E. 500 J

Ingxoxo
Unganaki ukumelana nomoya.
I-Diketahui :
Isisindo sebhola (m) = amagremu ayi-500 = 0,5 kg
Ijubane lokuqala (v)_o) = 10 m/s²
Ijubane lokugcina (v)_t) = 0. Uma ukuphakama okuphezulu, into imile okwesikhashana ngaphambi kokubuyela emuva.
Ukusheshisa ngenxa yamandla adonsela phansi (g) = 10 m/s²
Kubuziwe : Umsebenzi (W) owenziwe ngamandla adonsela phansi ebhola
Jawab :

Ithiyori yamandla e-work-kinetic :
I-work-kinetic energy theorem ithi umsebenzi ophelele noma ibhizinisi Ifomula yethiyori yamandla okusebenza-kinetic yamandla aphumayo entweni ifana noshintsho lwamandla okusebenza-kinetic ento.
W_Inani = ΔEK = EK_t – EK_o
W_Inani = ½ mv_t² – ½ mv_o² = ½ m (v_t² - v_o²)
Imininingwane:
EK_t = amandla okugcina e-kinetic, i-EK_o = amandla okuqala e-kinetic, m = isisindo sento, v_t = isivinini ukuphela kwento, v_o = ijubane lokuqala lento.
Umzamo ophelele :
Umsebenzi owenziwe ngamandla adonsela phansi ebhola kusukela ngesikhathi ibhola liphonswa kuze kube yilapho ibhola lifinyelela ukuphakama kwalo okuphezulu yilokhu:
W_Inani = ½ m (v_t² - v_o²) = ½ (0,5)(0² - 10²)
W_Inani = (0,25)(-100) = -25 AmaJoule
Uphawu olungeluhle lubonisa ukuthi indlela ibhola elihamba ngayo iphambene nendlela ibhola elihamba ngayo. Indlela ibhola elihamba ngayo iphezulu, kanti indlela ibhola elihamba ngayo iphansi. Amandla adonsela phansi Ukwenza umsebenzi ongemuhle ebholeni kusho ukuthi umsebenzi owenziwa ngamandla adonsela phansi ubangela ukuthi amandla adonsela phansi ebhola ande kanye namandla e-kinetic ebhola anciphe. Amandla adonsela phansi enza umsebenzi omuhle uma isiqondiso samandla adonsela phansi ebhola sifana nesiqondiso sokuhamba kwebhola (ibhola liyehla liye phansi).
Impendulo efanele ngu-C.

11. Ibhola elinesisindo esingu-1 kg liyawa ngaphandle kwesivinini sokuqala lisuka phezulu kwesakhiwo lidlule efasiteleni A esitezi esiphezulu liye efasiteleni B esitezi esingezansi ngomehluko wokuphakama ongu-2,5 m (g = 10 ms ^-2 ). Ungakanani umsebenzi owenziwayo ukuhambisa ibhola lisuka efasiteleni A liye efasiteleni B?

A. 5 Joule
B. 15 Joule
C. 20 Joule
D. 25 Joule
E. 50 AmaJoule

Ingxoxo
I-Diketahui :
Isisindo sebhola (m) = 1 kg
Ijubane lokuqala (v)_o) = 0 m/s
Ukuphakama (h) = amamitha ayi-2,5
Ukusheshisa ngenxa yamandla adonsela phansi (g) = 10 m/s²
Kubuziwe : Umsebenzi ophelele ngesikhathi sokunyakaza kwebhola
Jawab :
Ijubane lokugcina lebhola (v)_t)
Ibhola liwela ngaphandle kwejubane lokuqala, ngakho-ke ukunyakaza kwebhola kubhekwa njengokuwa okukhululekile. Okokuqala, bala ijubane lokugcina lebhola usebenzisa ifomula ukunyakaza kokuwa kwamahhalaKuyaziwa ukuthi ukusheshisa okubangelwa amandla adonsela phansi (g) = 10 m/s², ushintsho ekuphakameni kwebhola (h) = amamitha angu-2,5 kanye nesivinini sokugcina (v) siyabuzwa_t) ngakho-ke sebenzisa ifomula v_t² = 2 gh
v_t² = 2 gh = 2(10)(2,5) = 2(25)
v_t = √2(25) = 5√2
Ngakho ijubane lokugcina lebhola lingu-5√2 m/s
Umsebenzi ophelele = ushintsho kumandla e-kinetic
W_Inani = ΔEK = ½ m (v_t² - v_o²) = ½ (1){(5√2)² - 0²}
W_Inani = ½ (25)(2) = 25 amaJoule
Impendulo efanele ngu-D.

12. Into enesisindo esingu-2 kg iqala ukuhamba ngesivinini esingu-72 km/h.^-1Ngemva kokuhamba ngamamitha angu-400, ijubane lento liba ngu-144 km/h.^-1 kanye (g = 10 ms^-2). Umsebenzi ophelele owenziwe yinto ngaleso sikhathi…
A. 20 J
B. 60 J
C. 1.200 J
D. 2.000 J
E. 2.400 J
Ingxoxo
I-Diketahui :
Isisindo sento (m) = 2 kg
Ijubane lokuqala (v)_o) = 72 km/h = 20 m/s
Ijubane lokugcina (v)_t) = 144 km/h = 40 m/s
Ibanga elihanjiwe = amamitha ayi-400
Ukusheshisa ngenxa yamandla adonsela phansi (g) = 10 m/s²
Kubuziwe : Umzamo ophelele
Jawab :
Umsebenzi ophelele = ushintsho kumandla e-kinetic
W_Inani = ΔEK = ½ m (v_t² - v_o²) = ½ (2)(40² - 20²}
W_Inani = ½ (2)(1600 – 400) = 1200 amaJoules
Impendulo efanele ngu-C.

Ithiyori yamandla e-work-kinetic

13. Imoto enesisindo sethani eli-1 iqala lapho iphumule. Ngemva kwesikhashana ijubane layo lingu-5 m/s ^-1 . Inani lomsebenzi owenziwe yinjini yemoto...

A. 1000 Joule
B. 2.500 Joule
C. 5.000 Joule
D. 12.500 Joule
E. 25.000 AmaJoule

Ingxoxo

I-Diketahui :
Isisindo (m) = 1 ithani = 1000 kg
Ijubane lokuqala (v)_o) = 0 (imoto isuka esimweni sokungashintshi)
Ijubane lokugcina (v)_t) = 5 m/s
Kubuziwe : Uyini umsebenzi (W) owenziwa yinjini yemoto?
Jawab :

Ithiyori yamandla e-work-kinetic:
W_Inani = ½ m (v_t² - v_o²)
Umsebenzi owenziwa yinjini yemoto umi kanje:
W_Inani = ½ (1000)(5² - 0²) = (500)(25 – 0) = (500)(25) = 12.500 amaJoules
Impendulo efanele ngu-D.

Ithiyori Yomsebenzi Wamandla Nemishini

14. Bheka isithombe sokunyakaza kwezinto ngezansi!

Isisindo sento = 1 kg. Uma i-coefficient of kinetic friction phakathi kwebhulokhi kanye nephansi ingu-0,2, khona-ke inani lokufuduka kwento lingu… g = 10 m/s^2\

A. 10 m
B. 15 m
C. 20 m
D. 25 m
E. 30 m
Ingxoxo:
I-Diketahui :
m = 1 kg, g = 10 m/s²e_o = 10 m/s, v_t = 0
Kubuziwe :
Kuyini ukufuduka kwezinto?
Jawab :
Ithiyori yamandla okusebenza - yemishini :
Umsebenzi owenziwe ngamandla angewona awokugcina izinto = ushintsho emandleni okusebenza ento.
W_NC = I-EM₂ – I-EM₁
W_NC = (EP + EK)₂ – (EP + EK)₁ —- Isibalo 1
Amandla angewona awokugcina izinto ngendlela ehlelekile asebenza entweni yi-kinetic friction force:
W_NC =f_k s —- Isibalo 2
Ifomula yokungqubuzana kwe-Kinetic :

Faka esikhundleni u-f_k ku-equation 2 no-f_k ku-equation 3:
W_NC =f_k s = 2 imizuzwana
Ngesikhathi ihamba, into ibhekana noshintsho emandleni e-kinetic (amandla e-kinetic ayancipha) kuyilapho amandla e-gravitational potential ento engashintshi (ushintsho emandleni e-gravitational potential energy luyi-zero).
W_NC = (EK)₂ – (EK)₁ = ½ mv_t² – ½ mv_o² = ½ m (v_t² - v_o²)
2 s = ½(1)(0² - 10²)
2 s = (0,5)(100)
Amasekhondi angu-2 = 50
s = 50 / 2 = amamitha angu-25
Impendulo efanele ngu-D.

Umthetho wokulondolozwa kwamandla emishini

15. Umuntu oshwiba eqhweni uslayida esuka endaweni ephakeme A njengoba kuboniswe esithombeni esilandelayo:
Uma ijubane lokuqala lomshushuluzi = u-zero futhi ukusheshisa ngenxa yamandla adonsela phansi kungu-10 ms^-2, khona-ke isivinini somdlali ekuphakameni B...

A. √2 ms^-1
B. 5√2 ms^-1
C. 10√2 ms^-1
D. 20√2 ms^-1
E. 25√2 ms^-1

Ingxoxo
I-Diketahui :
Ijubane lokuqala (v)_o= = 0
Ukusheshisa ngenxa yamandla adonsela phansi (g) = 10 m/s²
Ushintsho ekuphakameni = amamitha angu-50 – amamitha ayi-10 = amamitha angu-40
Kubuziwe : isivinini somdlali ekuphakameni B?
Jawab :
Umthetho wokulondolozwa kwamandla emishini Isho lokho amandla okuqala omshini = amandla okugcina omshini.
Uma uqala ukusuka endaweni A, ijubane lokuqala lomshushuluzi = v_o = 0 ukuze amandla okuqala e-kinetic = EK_o = ½ mv_o² = 0. Ngokuphambene nalokho, uma efika endaweni A, umshwibi unamandla okuqala okudonsela phansi = EP_o = mgh, lapho h = amamitha angu-50. Ngakho-ke amandla okuqala omshini (EM)_o) = amandla okuqala adonsela phansi (EP)_o). Ngesikhathi sokuhamba kusuka ku-A kuya ku-B, ukuphakama komshushuluzi kuyehla, ngakho-ke amandla adonsela phansi ayancipha. Amandla adonsela phansi awalahleki kodwa aguqulwa abe amandla e-kinetic. Ukwanda kwamandla e-kinetic kuboniswa ukwanda kwejubane lomshushuluzi. Uma umshushuluzi efika phansi kokuthambekela, wonke amandla adonsela phansi aguqulwa abe amandla e-kinetic. Phansi kokuthambekela, amandla adonsela phansi ayi-zero, kuyilapho amandla e-kinetic esesilinganisweni sawo esiphezulu. Ngakho-ke amandla okugcina omshini (EM) akhona._t) = amandla okugcina e-kinetic (EK)_t).

Kuthiwani ngamandla adonsela phansi kanye namandla e-kinetic ephuzwini B? Ephuzwini B, amanye amandla adonsela phansi ayancipha futhi aguqulwa abe amandla e-kinetic. Ngokukhethekile, amandla e-kinetic ephuzwini B = ukwehla kwamandla adonsela phansi uma into kucatshangwa ukuthi iwela ngokukhululeka isuka ekuphakameni kwamamitha angu-40. Kungani ungasebenzisi ubude bendlela yendiza ethambekele kodwa ukuphakama kwamamitha angu-40? Uma ungakuqondi lokhu, kufanele ufunde izinto eziphathelene namandla alondolozayo kanye nobudlelwano bawo namandla angase abe khona kanye nomthetho wokulondolozwa kwamandla emishini.

Isivinini somshushuluzi ekuphakameni B:
Amandla okugcina omshini = amandla okuqala omshini
Amandla e-kinetic endaweni B = amandla adonsela phansi anamandla okuphakama kwamamitha angu-40
EK = EP
½ mv_t² = mgh
½ v_t² = gh
½ v_t² = (10)(50-10)
½ v_t² = (10)(40)
½ v_t² = 400
v_t² = (2)(400) = 800
v_t = √800 = √(2)(400) = 20√2 m/s
Impendulo efanele ngu-D.

16. Into isuka endaweni A ngaphandle kwejubane lokuqala. Uma kungekho ukungqubuzana ngesikhathi sokunyakaza, ijubane lento ephansi kakhulu...
A. 8 ms^-1
B. 12 ms^-1
C. 20 ms^-1
D. 24 ms^-1
E. 30 ms^-1
Ingxoxo
I-Diketahui :
Isisindo sento = m
Ijubane lokuqala (v)_o= = 0
Ukuphakama (h) = amamitha ayi-20
Ukusheshisa ngenxa yamandla adonsela phansi (g) = 10 m/s²
Kubuziwe : ijubane lokugcina (v_t)?
Jawab :
Amandla okuqala omshini (EM)₁) = amandla adonsela phansi ku-A (EP)_A) = mgh = (m)(10)(20) = 200 m
Amandla okugcina omshini (EM)₂) = amandla e-kinetic (EK) = ½ mv_t²
Isivinini sento endaweni ephansi kakhulu noma isivinini sokugcina sento u-v_t)?
Umthetho wokulondolozwa kwamandla emishini:
EM₁ = I-EM₂
200 m = ½ mv_t²
200 = ½ v_t²
400 = v_t²
v_t= 20m/s
Impendulo efanele ngu-C.

 

Umthombo wombuzo:

Imibuzo Yefiziksi Yezivivinyo Zikazwelonke Zesikole Samabanga Aphezulu/Isikole Samabanga Aphezulu Sokufundela Umsebenzi