Imibuzo eyisibonelo ye-Black Principle

Izibonelo eziyi-15 zemibuzo yezimiso eziyisisekelo zabamnyama

1. Iqhwa elinesisindo esingu-0,2 kg lixutshwa netiye elifudumele elinesisindo esingu-0,2 kg. Izinga lokushisa leqhwa = – 10 ^o C, izinga lokushisa letiye elifudumele = 40 ^o C. Ukushisa okuqondile kweqhwa = 2100 J/kg Co ^, ukushisa okuqondile kwamanzi = 4200 J/kg Co ^, ukushisa kokuhlanganiswa kwamanzi = 334.000 J/kg. Uma iqhwa netiye elifudumele kuxutshwe ohlelweni oluvaliwe oluhlukanisiwe, nquma izinga lokushisa lokugcina lengxube.

Ingxoxo
I-Diketahui :
Isisindo seqhwa (m es) = 0,2 kg
Isisindo samanzi etiye afudumele (itiye m) = 0,2 kg
Ukushisa kwamanzi okuqondile (c amanzi) = 4180 J/kg C^o
Ukushisa okuqondile kweqhwa (c es) = 2100 J/kg C^o
Ukushisa kokuhlanganiswa kwamanzi (L)_f amanzi) = 334.000 J/kg
Izinga lokushisa leqhwa (T es) = -10^oC
Izinga lokushisa lamanzi etiye elifudumele (itiye le-T) = 40^oC
Kubuziwe : izinga lokushisa lokugcina lengxube (ingxube ye-T) ?
Jawab :
Isinyathelo sokuqala, linganisa isimo sokugcina.
Ukushisa okumele kukhishwe ngamanzi ukuze kwehliswe izinga lokushisa elingu-0,2 kg wetiye elifudumele kusuka ku-40^oC kuya ku-0^oC:
Ukushisa okumuncwa yiqhwa elingu-0,2 kg ukuze kukhushulwe izinga lokushisa kusuka ku--10^oC kuya ku-0^oC:
Ukushisa kuncibilikiswa ukuze kuncibilikiswe u-0,2 kg weqhwa (ukushisa kuyadingeka ukushintsha lonke iqhwa libe ngamanzi):
Ngokusekelwe ekubalweni okungenhla, kutholakale imiphumela elandelayo:
I-Q ekhishwe = 33,444 kJ
I-Q etholiwe = 4,2 kJ
Ukuncibilika kwe-Q = 66,8 kJ

Uma itiye elishisayo likhipha ukushisa okungu-33,44 kJ, izinga lokushisa letiye elishisayo lishintsha kusuka ku-40oC kuya ku-0oC. Okunye kokushisa okukhishwe (cishe u-4,2 kJ) kusetshenziselwa ukuphakamisa izinga lokushisa leqhwa kusuka ku--10oC ^{kuya ku} -0oC ^. 33,44 kJ – 4,2 kJ = 29,24 kJ. Ukuze kuncibilikiswe lonke iqhwa emanzini, kudingeka ukushisa okungu-66,8 kJ. Ukushisa okusele kungu-29,24 kJ.

Kungaphethwa ngokuthi ukushisa okukhishwa yitiye elishisayo kusetshenziselwa kuphela ukuphakamisa izinga lokushisa leqhwa kusuka ku--10 ^° C kuya ku-0 ^° C nokuncibilikisa elinye iqhwa. Elinye iqhwa seliphenduke amanzi, kanti elinye alishintshi. Ngesikhathi senqubo yokushintsha kusuka kokuqinile kuya kokumanzi, izinga lokushisa alishintshi. Ngakho-ke, izinga lokushisa lokugcina lengxube lingu-0 ^° C.

2. Isisindo setiye elishisayo = 0,4 kg, isisindo seqhwa = 0,2 kg, izinga lokushisa lama-ice cubes = -10^oC, izinga lokushisa letiye elishisayo = 90^oC. Uma zombili zixubile, lingakanani izinga lokushisa lokugcina lenhlanganisela?
Ingxoxo
Isinyathelo sokuqala: linganisa isimo sokugcina
Ukushisa okumele kukhishwe ngamanzi ukuze kwehliswe izinga lokushisa elingu-0,4 kg wamanzi etiye ashisayo kusuka ku-90^oC kuya ku-0^oC:
Ukushisa okutholwa yi-0,2 kg yeqhwa ukuphakamisa izinga lokushisa kusuka ku--10^oC kuya ku-0^oC:
Ukushisa okudingekayo ukuze kuncibilikiswe iqhwa elingu-0,2 kg (ukushisa okudingekayo ukuze kuguqulwe lonke iqhwa libe ngamanzi):
Ngokusekelwe ekubalweni okungenhla, kutholakale imiphumela elandelayo:
I-Q ekhishwe = 150,48 kJ
I-Q etholiwe = 4,2 kJ
Ukuncibilika kwe-Q = 66,8 kJ
Uma itiye elishisayo likhipha ukushisa okungu-150,48 kJ, izinga lokushisa letiye elishisayo lishintsha kusuka ku-90oC kuya ku-0oC. Okunye kokushisa okukhishwe (4,2 J) kusetshenziselwa ukuphakamisa izinga lokushisa leqhwa kusuka ku--10 oC kuya ku-0oC. 150,48 kJ – 4,8 kJ = 146,28 kJ. Ukushisa okusele = 146,28 kJ.
Ukushisa okudingekayo ukuze kuncibilikiswe lonke iqhwa emanzini kungu-66,8 kJ kuphela. 146,28 kJ – 66,8 kJ = 79,48 kJ. Itiye elishisayo akudingeki likhiphe konke ukushisa kwalo kuze kube yilapho izinga lokushisa lalo lehla liye ku-0^oC. Ekuphetheni, izinga lokushisa lokugcina lengxube kumele libe ngaphezu kuka-0^oC.

Isinyathelo sesibili: thola izinga lokushisa lokugcina (T)
Ukushisa okudingekayo ukuphakamisa izinga lokushisa leqhwa kusuka ku--10^oC kuya ku-0^oI-C ingu-4200 J.
Ukushisa okudingekayo ukuze kuncibilikiswe lonke iqhwa emanzini (ukushisa okucashile) = 66.800 J
Ukushisa okudingekayo ukuphakamisa izinga lokushisa lamanzi (amanzi avela ekuncibilikiseni lonke iqhwa) kusuka ku-0^oKusukela ku-C kuya ku-T^oC = (isisindo seqhwa) (ukushisa kwamanzi okuthile) (T – 0) = (0,2) (4180) (T) = 836 T
Ukushisa okukhishwa yitiye elifudumele ukuze kwehliswe izinga lokushisa lalo kusuka ku-90oC kuya ku-T = (ubuningi bamanzi)(90-T) = (0,4)(4180)(90 - T) = 1672 (90-T) = 150.480 - 1672 T

 

3. Amagremu angu-60 amanzi ekushiseni okungu-90 ^o C (ukushisa okuthile kwamanzi = 1 cal.g ^-1 .o ^{C -1} ) axutshwa namagremu angu-40 amanzi afanayo ekushiseni okungu-25 ^o C. Uma kungekho ezinye izinto ezithinta le nqubo, khona - ke izinga lokushisa lokugcina lenhlanganisela...

A. 15,4 ^oC
B. 23,0 ^oC
C. 46,0 ^oC
D. 64,0 ^oC
E. 77,0 ^oC

Ingxoxo
I-Diketahui :
Isisindo samanzi 1 (m₁) = amagremu ayi-60
Izinga lokushisa lamanzi 1 (T)₁= = 90^oC
Isisindo samanzi 2 (m₂) = amagremu ayi-40
Izinga lokushisa lamanzi 2 (T)₂= = 25^oC
Ukushisa okukhethekile amanzi (c) = 1 cal.g^-1.^oC^-1
Kubuziwe : shu ingxube yokugcina
Jawab :
Ukushisa okukhishwa ngamanzi okushisa aphezulu (u-Q ukhishwe) = ukushisa okumuncwa amanzi okushisa aphansi (u-Q ukhishwe)
m₁ c (ΔT) = m₂ c (ΔT)
(60)(1)(90 – T) = (40)(1)(T – 25)
(60)(90 – T) = (40)(T – 25)
5400 – 60T = 40T – 1000
5400 + 1000 = 40T + 60T
6400 = 100T
T = 6400/100
T = 64^oC
Impendulo efanele ngu-D.

4. Ucezu lwe-aluminium lunesisindo esingamagremu angu-500 futhi lunezinga lokushisa elingama-30 ^oI-C ifakwa esitsheni esiqukethe amanzi anesisindo esingamagremu angu-200 kanye nokushisa okungama-90 ^oC. Uma ukushisa kwe-aluminium kwaziwa ukuthi kungu-0,22 cal/g C^o futhi ukushisa kwamanzi okuqondile kungu-1 cal/g C^o, khona-ke izinga lokushisa lokugcina lamanzi ne-aluminium...
A. 20,3 ^oC
B. 42,2 ^oC
C. 68,7 ^oC
D. 80,5 ^oC
E. 100 ^oC
Ingxoxo:
Iyunithi yobunzima, amagremu (g) ​​ayidingi ukuguqulwa ibe amakhilogremu (kg) ngoba ukushisa okuthile kwe-aluminium kanye nokushisa okuthile kwamanzi kuvezwa ku-cal/g C^o.
I-Diketahui :
i-aluminium m = amagremu angu-500
i-aluminium c = 0,22 cal/gC^o
I-aluminiyamu engu-T = 30 ^oC
amanzi = amagremu angu-200
amanzi = 1 cal/gC^o
Amanzi angu-T = 90 ^oC
Kubuziwe :
Izinga lokushisa lokugcina (T) lamanzi ne-aluminium?
Jawab :

Ifomula yokushisa : Q = (m)(c)(delta T)

Amanzi e-Q = = (amagremu angu-200)(1 cal/gC^o)(90 ^oC – T)
I-aluminium Q = (amagremu angu-500)(0,22 cal/gC^o)(T– 30 ^oC)

Ifomula eyisisekelo kaBlack : Q _ikhishwe = Q _imuncwe

Amanzi anezinga lokushisa eliphakeme lokuqala (90 ^oC) ukuze amanzi akhiphe ukushisa, i-aluminium inezinga lokushisa eliphansi lokuqala (30 ^oC) ukuze i-aluminium imunce ukushisa. Izinga lokushisa lokugcina lengxube yamanzi ne-aluminium kumele libe ngaphansi kwezinga lokushisa lokuqala lamanzi futhi libe phezulu kunezinga lokushisa lokuqala le-aluminium.
(200 amagremu)(1 cal/gC^o)(90 ^oC – T) = (amagremu angu-500)(0,22 cal/g C^o)(T– 30 ^oC)
(200)(1)(90-T) = (500)(0,22)(T-30)
(200)(90-T) = (110)(T-30)
18000 – 200 T = 110 T – 3300
18000 + 3300 = 110 T + 200 T
21300 = 310 T
T = 68,7 ^oC
Izinga lokushisa lokugcina lokuhlanganiswa kwamanzi ne-aluminium lingu-68,7 ^oC.
Impendulo efanele ngu-C.

5. Ucezu lwensimbi olunesisindo esingamagremu angu-300 ekushiseni okungu-80 ^oC ecwiliswe kumagremu angu-200 amanzi ku-40 ^oC. Ukushisa kwamanzi okuqondile = 1 cal/g C^oUma izinga lokushisa lokugcina lengxube yensimbi namanzi lingu-50^o Uma isitsha singamunci ukushisa, khona-ke ukushisa kwensimbi okuqondile...
A. 0,15 cal/g C^o
B. 0,22 cal/g C^o
C. 1,50 cal/g C^o
D. 4,8 cal/g C^o
E. 7,2 cal/g C^o
Ingxoxo:
I-Diketahui :
insimbi m = amagremu angu-300
Insimbi engu-T = 80 ^oC
amanzi = amagremu angu-200
Amanzi angu-T = 40 ^oC
amanzi = 1 cal/g C^o
Ingxube yokugcina yensimbi namanzi = 50 ^oC
Kubuziwe :
insimbi?
Jawab :
Insimbi ye-Q = (m)(c)(delta T) = (300 amagremu)(c insimbi)(80^oC - 50^oC) = (amagremu angu-300)(c insimbi)(30 C^o)
Amanzi e-Q = (m)(c)(delta T) = (200 amagremu)(1 cal/g C^o)(60^oC - 50^oC) = (amagremu angu-200)(1 cal/g C^o)(10 C^o)

Ifomula eyisisekelo kaBlack : Q _ikhishwe = Q _imuncwe

Insimbi inezinga lokushisa eliphezulu lokuqala (80 ^oC) ukuze insimbi ikhiphe ukushisa, amanzi abe nokushisa okuphansi kokuqala (40 ^oC) ukuze amanzi amunce ukushisa.
(300 amagremu)(c insimbi)(30 C^o) = (amagremu angu-200)(1 cal/g C^o)(10 C^o)
(300)(c)(30) = (200)(1)(10)
9000 c = 2000
c = 2000 / 9000
c = 0,22 cal/g C^o
Ukushisa okuqondile kwensimbi kungu-0,22 cal/g C^o.
Impendulo efanele ingu-B.

6. Amabhola amabili afanayo anokushisa okufanayo okungu-40 ^oC, amabhola amabili anobunzima obungamagremu ayi-10 kanye namagremu angama-40 ngokulandelana. Womabili amabhola afakwa oketshezini, ukuze izinga lokushisa lamabhola womabili lenyuke lifike kuma-degrees angu-60.^oC. Uma ukushisa kwebhola kungama-2 cal/gr C^o kanye nekhalori eli-1 = ama-Joules angu-4,2, khona-ke umehluko ekushiseni okumuncwa yibhola ngalinye...
A. 5,04 x 10³ Joule
B. 7,50 x 10³ Joule
C. 10,6 x 10³ Joule
D. 40 x 10³ Joule
E. 42 x 10³ Joule
Ingxoxo:
I-Diketahui :
m₁ = 10 amagremu
m₂ = 40 amagremu
T₁ =T₂ = 40 ^oC
T _ukuphela = 60 ^oC
ibhola le-c = 2 cal/gr C^o
Kubuziwe :
Uyini umehluko ekushiseni okumuncwa yibhola ngalinye?
Jawab :
Izinga lokushisa lamabhola womabili liyakhuphuka ngoba womabili amabhola kumele amunce ukushisa.
Q₁ = (10 gr)(2 cal/gr C^o)(60^oC–40^oC) = (10 gr)(2 cal/gr C^o)(20 C^o) = 400 cal = (400) (4,2 J) = 1680 Joules
Q₂ = (40 gr)(2 cal/gr C^o)(60^oC–40^oC) = (40 gr)(2 cal/gr C^o)(20 C^o) = 1600 cal = (1600) (4,2 J) = 6720 Joules
Umehluko ekushiseni okumuncwa yibhola ngalinye:
6720 J – 1680 J = 5040 J = 5,04 x 10³ J
Impendulo efanele ngu-A.

7. Amanzi anesisindo esingamagremu angu-200 ekushiseni okungama-30°C axutshwa namanzi abilayo anesisindo esingamagremu ayi-100 kanye nesilinganiso sokushisa esingama-90°C. (Ukushisa okuqondile kwamanzi = 1 cal.gram ^-1 °C ^-1 ). Izinga lokushisa lamanzi axubile ngesikhathi sokulingana kokushisa lingu….

A. 10°C

B. 30°C

C. 50°C

D. 75°C

E. 150°C

Ingxoxo

Kuyaziwa ukuthi :

Isisindo samanzi 1 (m1 ₎ = 200 amagremu

Izinga lokushisa lamanzi 1 (T1 ₎ = 30 ^o C

Isisindo samanzi 2 (m2 ₎ = 100 amagremu

Izinga lokushisa lamanzi 2 (T2 ₎ = 90 ^o C

Ukushisa kwamanzi okuqondile (c) = 1 cal.gram ⁻¹ °C ⁻¹

Kubuziwe : izinga lokushisa lokugcina lengxube

Impendulo :

Ukushisa okukhishwa ngamanzi okushisa aphezulu (u-Q ukhishwe) = ukushisa okumuncwa amanzi okushisa aphansi (u-Q ukhishwe)

Impendulo efanele ngu-C.

8. Amagremu angu-60 amanzi ekushiseni okungu-90 ^o C (ukushisa okuthile kwamanzi = 1 cal.g ^-1 .o ^{C -1} ) axutshwa namagremu angu-40 amanzi afanayo ekushiseni okungu-25 ^o C. Uma kungekho ezinye izinto ezithinta le nqubo, khona - ke izinga lokushisa lokugcina lenhlanganisela...

A. 15,4 ^o C

B. 23,0 ^o C

C. 46,0 ^o C

D. 64,0 ^o C

E. 77,0 ^o C

Ingxoxo

Kuyaziwa ukuthi :

Isisindo samanzi 1 (m1 ₎ = 60 amagremu

Izinga lokushisa lamanzi 1 (T1 ₎ = 90 ^o C

Isisindo samanzi 2 (m2 ₎ = 40 amagremu

Izinga lokushisa lamanzi 2 (T2 ₎ = 25 ^o C

Ukushisa kwamanzi okuthile (c) = 1 ^{cal.g -1} .o C ^-1

Kubuziwe : izinga lokushisa lokugcina lengxube

Impendulo :

Ukushisa okukhishwa ngamanzi okushisa aphezulu (u-Q ukhishwe) = ukushisa okumuncwa amanzi okushisa aphansi (u-Q ukhishwe)

Impendulo efanele ngu-D.

9. Iqhwa elinesisindo esingu-M grams ekushiseni okungu-0 ^o C, lifakwa emanzini anesisindo esingu-340 grams ekushiseni okungu-20 ^o C elibekwa esitsheni esikhethekile. Ake sithi isitsha asimunci/asikhiphi ukushisa. Uma _{iqhwa elingu} -L = 80 cal g ^-1 , _amanzi angu-c = 1 cal g ^{-1 o} C ^-1 , lonke iqhwa liyancibilika bese kulinganiswa kokushisa kufinyelelwa ekushiseni okungu-5 ^o C, khona-ke isisindo seqhwa (M)...

A. 60 amagremu

B. 68 amagremu

C. 75 amagremu

D. 80 amagremu

E. 170 amagremu

Ingxoxo

Kuyaziwa ukuthi :

Isisindo samanzi (m) = 340 amagremu

Izinga lokushisa leqhwa (T _es ) = 0 ^o C

Izinga lokushisa lamanzi ( _amanzi angu-T ) = 20 ^° C

Izinga lokushisa lokulingana kokushisa (T) = 5 ^o C

Ukushisa kweqhwa elincibilikayo ( _iqhwa eli-L ) = 80 cal g ^-1

Ukushisa kwamanzi okuthile (c _amanzi ) = 1 cal g ^{-1 o} C ^-1

Umbuzo : Isisindo seqhwa (M)

Impendulo :

Isimiso sikaBlack sithi ohlelweni oluvaliwe oluhlukanisiwe, ukushisa okukhishwa yinto enokushisa okuphezulu kufana nokushisa okumuncwa yinto enokushisa okuphansi.

Ukushisa okukhishwa ngamanzi (u-Q ukhishwa) = ukushisa okumuncwa yiqhwa (u-Q ukhishwa)

Impendulo efanele ngu-A.

Catatan:

Uma kuthiwa iqhwa lisekushiseni okungu-0 ^o kusho ukuthi amanzi asesekushiseni okungu-0 ^o C kusho ukuthi amanzi asekushiseni okuwuketshezi. Hlukanisa ukusetshenziswa kwamagama athi iqhwa namanzi. Ngenxa yokuthi amanzi asesekushiseni okuwuketshezi, ukushisa okumuncwa kuqala kusetshenziselwa ukuncibilikisa lonke iqhwa libe ngamanzi, ngakho-ke ohlangothini lwesokudla lwesibalo esingenhla kunefomula eyongezwayo ukuze kubalwe inani lokushisa elizoncibilikisa iqhwa (m _es L _es ). Ngemva kokuba lonke iqhwa lincibilike libe ngamanzi, kusetshenziswa ukushisa okwengeziwe ukuphakamisa izinga lokushisa leqhwa kusuka ku-0 ^o C kuya ku-5 ^o C.

10. Insimbi yethusi ekushiseni okungu-100 ^o C ifakwa emanzini anesisindo esingu-128 amagremu kanye nokushisa okungu-30 ^o C. Ukushisa okuqondile kwamanzi kungu-1 cal.g ^-1o C ^-1 kanti ukushisa okuqondile kwethusi kungu-0,1 cal.g ^-1o C ^-1 . Uma ukulingana kokushisa kwenzeka ekushiseni okungu-36 ^o C, khona-ke isisindo sensimbi….

A. 140 amagremu

B. 120 amagremu

C. 100 amagremu

D. 80 amagremu

E. 75 amagremu

Ingxoxo

Kuyaziwa ukuthi:

Izinga lokushisa lethusi (T ₁ ) = 100 ^o C

Ukushisa okuqondile kwethusi (c ₁ ) = 0,1 cal.g ^-1o C ^-1

Isisindo samanzi (m2 ₎ = 128 amagremu

Izinga lokushisa lamanzi (T2 ₎ = 30 ^o C

Ukushisa kwamanzi okuqondile (c ₂ ) = 1 cal.g ^-1o C ^-1

Izinga lokushisa lokulingana kokushisa (T) = 36 ^o C

Umbuzo: Isisindo sethusi (m ₁ )

Impendulo:

Isimiso sikaBlack sithi ukushisa okukhishwa yinto enokushisa okuphezulu = ukushisa okutholwa yinto enokushisa okuphansi.

Impendulo efanele ingu-B.

11. Amakhilogremu amathathu enduku emnyama enomthofu enokushisa okuthile okungu-1400 J.kg ^-1 C ^-1 ekushiseni okungu-80 ^o C acwiliswa ku-10 kg wamanzi ngokushisa okuthile okungu-4200 J.kg ^-1 C ^-1 . Ngemva kokulingana kokushisa, izinga lokushisa lokugcina lengxube lingu-20 ^o C. Izinga lokushisa lokuqala lamanzi lingu….

A. 20 ^o C

B. 18 ^o C

C. 14 ^o C

D. 12 ^o C

E. 10 ^o C

Ingxoxo

Kuyaziwa ukuthi:

Isisindo somthofu (m ₁ ) = 3 kg

Ukushisa okuqondile kwethini (c ₁ ) = 1400 J.kg ^-1 C ^-1

Izinga lokushisa le-tin (T ₁ ) = 80 ^o C

Isisindo samanzi (m2 ₎ = 10 kg

Ukushisa kwamanzi okuqondile (c ₂ ) = 4200 J.kg ^-1 C ^-1

Izinga lokushisa lokulingana kokushisa (T) = 20 ^o C

Okufunwayo: Izinga lokushisa lamanzi lokuqala ( _T2 )

Impendulo:

Impendulo efanele ngu-C.

12. Uhlamvu lwemali olungamagremu angu-50 lushiswa lufike ezingeni lokushisa elingu-85 ^o C, bese lucwiliswa esitsheni esiqukethe amagremu angu-50 amanzi ezingeni lokushisa elingu-29,8 ^o C (ukushisa okuthile kwamanzi = 1 cal.g ^-1 .o ^{C -1} ). Uma izinga lokushisa lokugcina lesistimu lingu-37 ^o C futhi kucatshangwa ukuthi akukho shintsho ekushiseni ngesitsha, khona-ke ukushisa okuthile kwensimbi...

A. 0,12 cal.g ^-1 . ^o C ^-1

B. 0,30 cal.g ^-1 . ^o C ^-1

C. 1,50 cal.g ^-1 . ^o C ^-1

D. 4,8 cal.g ^-1 . ^o C ^-1

^E. 7,2 cal.g ^-1 .o C ^-1

Ingxoxo

Kuyaziwa ukuthi:

Isisindo semali (m) = 50 amagremu

Izinga lokushisa lokuqala lemali (T ₁ ) = 85 ^o C

Isisindo samanzi (m) = 50 amagremu

Izinga lokushisa lamanzi lokuqala (T2 ₎ = 29,8 ^o C

Ukushisa kwamanzi okuqondile = 1 ^{cal.g -1} .o C ^-1

Izinga lokushisa lokugcina lesistimu (T) = 37 ^o C

Umbuzo: Ukushisa okuqondile kwensimbi (c)

Impendulo:

Isimiso sikaBlack sithi ukushisa okukhishwayo = ukushisa okumuncwayo. Ukushisa kukhishwa yinhlamvu yezinhlamvu zemali bese ukushisa kumuncwa ngamanzi, kuze kube yilapho kufinyelelwa ukulingana kokushisa.

Wonke amayunithi achazwa ngamagremu ngakho asikho isidingo sokuguqula amayunithi.

I-Q _ikhishwe = I-Q _imuncwe

m _insimbi c ΔT = m _amanzi c ΔT

(50)(c)(85-37) = (50)(1)(37-29,8)

(50)(c)(48) = (50)(7,2)

(50)(c)(48) = (50)(7,2)

(c)(48) = 7,2

c = 7,2 / 48

c = 0,15 cal.g ^-1 . ^o C ^-1

13. Insimbi yethusi ekushiseni okungu-100 ^o C ifakwa emanzini anesisindo esingu-128 amagremu kanye nokushisa okungu-30 ^o C. Ukushisa okuqondile kwamanzi kungu-1 cal.g ^{-1 o} C ^-1 kanti ukushisa okuqondile kwethusi kungu-0,1 cal.g ^{-1 o} C ^-1 . Uma ukulingana kokushisa kwenzeka ekushiseni okungu-36 ^o C, khona-ke isisindo sensimbi….

A. 140 amagremu
B. 120 amagremu
C. 100 amagremu
D. 80 amagremu
E. 75 amagremu

Ingxoxo
Kuyaziwa ukuthi:
Izinga lokushisa lethusi (T)₁= = 100 ^oC
Ukushisa okuqondile kwethusi (c)₁) = 0,1 cal.g^{-1 o}C^-1

Isisindo samanzi (m₂) = amagremu ayi-128
Izinga lokushisa lamanzi (T)₂= = 30 ^oC
Ukushisa kwamanzi okuthile (c)₂) = 1 cal.g^{-1 o}C^-1

Izinga lokushisa lokulingana kokushisa (T) = 36 ^oC
Umbuzo: Isisindo sethusi (m₁)
Impendulo:

Isimiso sikaBlack sithi ukushisa okukhishwa yinto enokushisa okuphezulu = ukushisa okutholwa yinto enokushisa okuphansi.
Ithusi lika-Q = amanzi ka-Q
m₁ c₁ ΔT = m₂ c₂ ΔT
(m₁)(0,1)(100-36) = (128)(1)(36-30)
(m₁)(0,1)(64) = (128)(1)(6)
(m₁)(6,4) = 768
m₁ = 768/6,4
m₁ = 120
Isisindo sethusi singamagremu ayi-120.
Impendulo efanele ingu-B.

14. Amakhilogremu amathathu enduku emnyama enomthofu enokushisa okuthile okungu-1400 J.kg ^-1 C ^-1 ekushiseni okungu-80 ^o C acwiliswa ku-10 kg wamanzi ngokushisa okuthile okungu-4200 J.kg ^-1 C ^-1 . Ngemva kokulingana kokushisa, izinga lokushisa lokugcina lengxube lingu-20 ^o C. Izinga lokushisa lokuqala lamanzi lingu….

A. 20 ^oC
B. 18 ^oC
C. 14 ^oC
D. 12 ^oC
E. 10 ^oC

Ingxoxo
Kuyaziwa ukuthi:
Isisindo somthofu (m₁) = 3 kg
Ukushisa okukhethekile kwethini (c)₁) = 1400 J.kg^-1 C^-1
Izinga lokushisa le-tin (T)₁= = 80 ^oC

Isisindo samanzi (m₂) = 10 kg
Ukushisa kwamanzi okuthile (c)₂) = 4200 J.kg^-1 C^-1

Izinga lokushisa lokulingana kokushisa (T) = 20 ^oC
Okufunwayo: Izinga lokushisa lamanzi lokuqala (T)₂)
Impendulo:
I-Q ikhishwe = I-Q itholiwe
Ithini lika-Q = amanzi ka-Q
m₁ c₁ ΔT = m₂ c₂ ΔT
(3)(1.400)(80-20) = (10)(4.200)(20-T)
(4.200)(60) = (42.000)(20-T)
252.000 = 840.000 – 42.000 T
42.000 T = 840.000 – 252.000
42.000 T = 588.000
T = 588.000 / 42.000
T = 14
Izinga lokushisa lokuqala lamanzi lingu-14^oC.
Impendulo efanele ngu-C.

15. Iqhwa elinesisindo esingu-M grams ekushiseni okungu-0 ^o C, lifakwa emanzini anesisindo esingu-340 grams ekushiseni okungu-20 ^o C elibekwa esitsheni esikhethekile. Ake sithi isitsha asimunci/asikhiphi ukushisa. Uma _{iqhwa elingu} -L = 80 cal g ^-1 , _amanzi angu-c = 1 cal g ^{-1 o} C ^-1 , lonke iqhwa liyancibilika futhi ukulingana kokushisa kufinyelelwa ekushiseni okungu-5 ^o C, khona-ke isisindo seqhwa (M)...

A. 60 amagremu
B. 68 amagremu
C. 75 amagremu
D. 80 amagremu
E. 170 amagremu

Ingxoxo
I-Diketahui :
Isisindo samanzi (m) = 340 amagremu
Izinga lokushisa leqhwa (T)_es= = 0^oC
Suhu amanzi (T)_air= = 20^oC
Izinga lokushisa lokulingana kokushisa (T) = 5^oC
Ukushisa kokuhlanganiswa kweqhwa (L)_es) = 80 cal g^-1
Ukushisa kwamanzi okuthile (c)_air) = 1 cal g^{-1 o}C^-1
Kubuziwe : Isisindo seqhwa (M)
Jawab :

Umgomo Omnyama ithi ohlelweni oluvaliwe oluhlukanisiwe, ukushisa okukhishwa yinto enokushisa okuphezulu kufana nokushisa okumuncwa yinto enokushisa okuphansi.
Ukushisa okukhishwa ngamanzi (u-Q ukhishwa) = ukushisa okumuncwa yiqhwa (u-Q ukhishwa)
m_air c_air (T) = m_es L_es +m_es c_air (T)
(340)(1)(20-5) = M (80) + M (1)(5-0)
(340)(15) = 80M + 5M
5100 = 85M
M = 5100/85
M = amagremu angu-60
Impendulo efanele ngu-A.

Catatan:
Uma kuthiwa iqhwa linokushisa okungu-0^o khona-ke amanzi asesesesimweni esiqinile. Uma kuthiwa izinga lokushisa lamanzi lingu-0^oC bese amanzi esesimweni soketshezi. Hlukanisa ukusetshenziswa kwamagama athi iqhwa namanzi. Ngenxa yokuthi amanzi asesesimweni esiqinile noma seqhwa, ukushisa okumuncwa kuqala kusetshenziselwa ukuncibilikisa lonke iqhwa libe ngamanzi, ngakho-ke ohlangothini lwesokudla lwesibalo esingenhla, kunezelwa ifomula yokubala inani lokushisa elizoncibilikisa iqhwa (m_es L_esNgemva kokuba lonke iqhwa selincibilikile laba ngamanzi, kusetshenziswa ukushisa okwengeziwe ukuphakamisa izinga lokushisa leqhwa kusuka ku-0.^oU-C uba ngu-5^oC.

Umthombo wombuzo:

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