Mehlala ea lipotso mabapi le mocheso le liphetoho boemong

Mehlala e 15 ea mocheso le liphetoho boemong

Puisano ea Mathata a Mocheso

1. Ho eketsa mocheso oa metsi a leoatle ka 1°C hoa hlokahala mocheso Li-joule tse 3900. Haeba mocheso o itseng metsi a leoatle 3,9 × 10³ J/Kg°C, joale boima ba metsi a leoatle ke…

A. 100 kg

B. 10 kg

C. 1 kg

D. 0,1 kg

Puisano

Hoa tsebahala hore:

Liphetoho tsa mocheso (ΔT) = 1^oC

Mocheso (Q) = 3900 Joule

Mocheso o itseng oa metsi a leoatle (c) = 3,9 x 10³ J/Kg°C = 3900 J/Kg°C

O botsitse: Boima ba metsi a leoatle (m)

Karabo:

Foromo ea mocheso:

Q = mc ΔT

Tlhaloso: Q = mocheso, m = boima, c = mocheso o itseng, ΔT = phetoho mochesong

m = Q / c ΔT = 3900 / (3900)(1) = 3900 / 3900 = 1

Kahoo boima ba metsi a leoatle (m) = 1 kilograma

Karabo e nepahetseng ke C.

2. Koporo e boima ba 2 kg mochesong oa 30°C. E amohela 39.000 J ea mocheso. Haeba mocheso o itseng oa koporo e le 390 J/kg °C, joale mocheso oa ho qetela oa koporo ke...

A. 80°C

B. 50°C

C. 30°C

D. 20°C

Puisano

Hoa tsebahala hore:

Boima (m) = 2 kg

Mocheso oa pele (T)₁= 30^oC

Mocheso o monyelang (Q) = 39.000 Joules

Mocheso o itseng (c) oa koporo = 390 J/kg ^oC

O botsitse: Mocheso oa ho qetela oa koporo (T)₂)

Karabo:

Foromo ea mocheso:

Q = mc ΔT

Tlhaloso: Q = mocheso, m = boima, c = mocheso o itseng, ΔT = phetoho mochesong

Q = mc ΔT = mc (T₂ - T₁)

39.000 = (2)(390)(T)₂ - 30)

100 = (2)(1)(T₂ - 30)

100 = (2)(T₂ - 30)

50 = T₂ - 30

T₂ = 50 + 30

T₂ = 80^oC

Karabo e nepahetseng ke A.

3. Ho phahamisa mocheso oa 5 kg ea metsi ho tloha ho 15°C ho isa ho 40°C, mocheso o hlokahalang ke….

(mocheso o itseng oa metsi 4,2 × 10³ J/Kg°C)

A. 525.000 J

B. 420.000 J

C. 150.000 J

D. 21.000 J

Puisano

Hoa tsebahala hore:

Boima (m) = 5 kg

Mocheso oa pele (T)₁) = 15°C

Mocheso oa ho qetela (T)₂) = 40°C

Mocheso o itseng oa metsi (c) = 4,2 × 10³ J/kg°C

O botsitse: Mocheso (Q)

Karabo:

Foromo ea Mocheso:

Q = mc ΔT

Q = (5 kg)(4,2 × 10³ J/kg°C(40°C – 15°C)

Q = (5)(4,2 × 10³ J(25)

Q = 525 x 10³ J

Q = 525.000 Joule

Karabo e nepahetseng ke A.

4. 2 kg ea metsi ho tloha mochesong oa 24°C e futhumatsoa ho fihlela ho 90°C. Haeba mocheso o itseng e le 4.200 Joules/kg°C, joale mocheso o amoheloang ke metsi ke...

A. 336.000 Joule

B. 259.200 Joule

C. 554.400 Joule

D. 543.600 Joule

Puisano

Hoa tsebahala hore:

Boima ba metsi (m) = 2 kg

Mocheso oa pele (T)₁) = 24°C

Mocheso oa ho qetela (T)₂) = 90°C

Mocheso o itseng oa metsi (c) = 4.200 Joules/kg°C

O botsitse: Mocheso (Q) o amoheloang ke metsi ke….

Karabo:

Likhalori:

Q = m c ΔT

Q = (2 kg)(4.200 Joules/kg°C(90°C – 24°C)

Q = (2 kg)(4.200 Joules/kg°C(66°C)

Q = (132)(4.200 Joule)

Q = 554.400 Joule

Karabo e nepahetseng ke C.

5. Metsi a boima ba digrama tse 5 a futhumatswa ho tloha ho 10°C ho isa ho 40°C. Haeba mocheso o itseng wa metsi e le 1 cal/gr°C, mocheso o hlokahalang ho phahamisa mocheso wa metsi ke...

A. Likhalori tse 100

B. Likhalori tse 150

C. Likhalori tse 200

D. Likhalori tse 400

Puisano

Hoa tsebahala hore:

Boima (m) = digrama tse 5

Mocheso oa pele (T)₁= 10^oC

Mocheso oa ho qetela (T)₂= 40^oC

Mocheso o itseng oa metsi (c) = 1 cal/gr°C

O botsitse: Mocheso o hlokahalang ho phahamisa mocheso oa metsi

Karabo:

Foromo ea mocheso:

Q = mc ΔT

Q = (ligrama tse 5)(1 cal/gr°C(40)^oC - 10^oC)

Q = (5)(Likhalori tse 1(30)

Q = lik'hilojule tse 150

Karabo e nepahetseng ke B.

6. Mokhanni oa mocheso o motle ka ho fetisisa ke ...

A. aluminium

B. mercury

C. tšepe

D. khalase

Puisano

Hore na thepa e tsamaisa mocheso hantle kapa che ho itshetlehile ka mofuta wa thepa. Bongata ba mmele bo bontshang bokgoni ba thepa ba ho tsamaisa mocheso bo bitswa ho tsamaisa mocheso. Ha ho tsamaisa mocheso ho le hodimo, bokgoni ba thepa ba ho tsamaisa mocheso bo ba betere.

Ka tlase ke boleng ba conductivity ea mocheso oa thepa e 'maloa:

Aluminium = 200 J/ms C^o

Tšepe = 40 J/ms C^o

Mercury = 8,30 J/ms C^o

Khalase = 0,84 J/ms C^o

Ho latela lintlha tse ka holimo, boleng bo boholo ka ho fetisisa ba conductivity ea mocheso ke aluminium.

Karabo e nepahetseng ke A.

7. 0,2 kg ea metsi mochesong oa likhato tse 25^oC e futhumatsoa ka mocheso oa 42.000 Joules. Haeba mocheso o itseng oa metsi = 4200 J/kg ^oC, joale mocheso oa ho qetela oa metsi ke…..

A. 100^oC

B. 80^oC

C. 75^oC

D. 50^oC

Puisano

Diyuniti tsohle di hlahiswa ka diyuniti tsa Matjhaba ntle le diyuniti tsa mocheso tse setseng ka Celsius hobane mocheso o sebedisa yuniti J/kg. ^oC.

Hoa tsebahala hore:

Boima ba metsi (m) = 0,2 kg

Mocheso (Q) = 42.000 Joule

Mocheso o itseng oa metsi (c) = 4200 J/kg ^oC

Mocheso oa pele (T)₁= 25^oC

O botsitse: Mocheso oa ho qetela (T)₂)

Karabo:

Foromo ea mocheso:

Q = mc ΔT = mc (T₂ - T₁)

Tlhaloso ea foromo:

Q = mocheso, m = boima, c = mocheso o itseng, ΔT = phetoho mochesong, T₁ = mocheso oa pele, T₂ = mocheso oa ho qetela

Mocheso oa ho qetela oa metsi ke:

Q = mc (T)₂ - T₁)

42.000 = (0,2)(4200)(T₂ - 25)

42.000 = 840 (T₂ - 25)

42.000 = 840 T₂ - 21.000

42.000 + 21.000 = 840 T₂

63.000 = 840 T₂

T₂ = 63.000/840

T₂ = 75^oC

Karabo e nepahetseng ke C.

Liphetoho Mochesong le Liphetoho Sebopehong

8. Ho latela kerafo, mocheso o hlokahalang ke 5 kg ea metsi ts'ebetsong ho tloha ho C ho isa ho D (mocheso o itseng oa metsi = 4.200 J/kg ^oC) ke…

A. 210.000 J

B. 420.000 J

C. 21.000.000 J

D. 42.000.000 J

Puisano

Hoa tsebahala hore:

Boima ba metsi (m) = 5 kg

Mocheso o itseng oa metsi (c) = 4200 J/kg ^oC

Mocheso oa pele (T)₁= 0 ^oC

Mocheso oa ho qetela (T)₂= 10 ^oC

Liphetoho tsa mocheso (ΔT) = 10 ^oC - 0 ^oEA-10-C ^oC

O botsitse: Mocheso o monyang (Q)

Karabo:

Foromo ea mocheso:

Q = mc ΔT = (5 kg)(4200 J/kg ^oC)(10 ^oC) = (5)(4200 J)(10) = (50) (4200 J) = 210.000 Joules

Karabo e nepahetseng ke A.

9. Sheba kerafo ka lehlakoreng! Ho hlokahala mocheso o mokae ho fetola ligrama tse 200 tsa leqhoa ts'ebetsong ea A ho ea ho C, haeba mocheso o itseng oa leqhoa e le 2100 J/kg ^oC mme mocheso wa ho kopana ha leqhoa ke 336.000 J/kg ke…..

A. 4.200 Joule

B. 67.200 Joule

C. 71.400 Joule

D. 75.600 Joule

Puisano

Hoa tsebahala hore:

Diyuniti tsohle di lokela ho hlahiswa Tsamaisong ya Matjhaba ya Diyuniti.

Boima ba leqhoa (m) = 200 grams = 200/1000 khilogremu = 0,2 khilogremu

Mocheso o itseng (c) = 2100 J/kg ^oC

Mocheso oa ho kopana ha leqhoa (L)_F) = 336.000 J/kg

O botsitse: Palo ea mocheso o hlokahalang ts'ebetsong ho tloha ho A ho isa ho C

Karabo:

Ts'ebetsong ea A ho isa ho B, mocheso o monngoa ke leqhoa ho eketsa mocheso oa lona ho tloha ho -10^oC e ba 0^oC.

Palo ea mocheso o monngoang ts'ebetsong ea A ho isa ho B e baloa ho sebelisoa foromo ea mocheso:

Q = mc ΔT

Tlhaloso ea foromo: Q = mocheso o monyelitsoeng, m = boima ba leqhoa, c = mocheso o itseng oa leqhoa, ΔT = phetoho mochesong

Kahoo tekanyo ea mocheso o monngoang ke:

Q₁ = mc ΔT = (0,2)(2100(0-(-10) = (0,2)(2100)(10) = (2)(2100) = 4200 Dijoule

Mekhoeng ea B ho isa ho C, mocheso o monngoa ho qhibilihisa leqhoa lohle hore e be metsi. Mokhoeng ona, ho etsahala phetoho feela boemong, 'me ha ho phetoho mochesong. Mocheso oa leqhoa le metsi o lula ho 0°C.^oC.

Palo ea mocheso o monngoang ts'ebetsong ea B ho isa ho C e baloa ho sebelisoa foromo ea mocheso:

Q₂ = m L_F = (0,2 kg)(336.000 J/kg) = 67200 Joule

Palo ea mocheso o monngoang ts'ebetsong ho tloha ho A ho isa ho C:

P = P₁ +Q₂ = Lijoule tse 4200 + Lijoule tse 67200 = Lijoule tse 71400

Karabo e nepahetseng ke C.

10. Ela hloko kerafo e latelang ea liphetho tsa liteko!

Haeba 2 kg ea metsi e futhumetse, 'me mocheso oa mouoane oa metsi = 2,27 x 10⁶ J/kg, mocheso o itseng oa metsi = 4.200 J/kg ^oC le kgatello ya moya ya sepakapaka se le seng, ebe mocheso o hlokahalang bakeng sa tshebetso ho tloha ho B ho ya ho C ke...

A. 3.360 lik'hilojoule

B. 4.540 lik'hilojoule

C. 4.876 lik'hilojoule

D. 5.212 lik'hilojoule

Puisano

Hoa tsebahala hore:

Boima ba metsi (m) = 2 kg

Mocheso oa mouoane oa metsi (L)_V) = 2,27 x 10⁶ J / lik'hilograma

Mocheso o itseng oa metsi (c) = 4.200 J/kg ^oC

O botsitse: Palo ea mocheso o monngoang bakeng sa ts'ebetso ho tloha ho B ho isa ho C.

Karabo:

Ts'ebetsong ea A ho isa ho B, mocheso o monngoang ke metsi o sebelisoa ho phahamisa mocheso oa metsi ho tloha ho 60^oHo tloha ho C ho isa ho 100^oC. Ka kgatello ya moya ya sepakapaka se le seng, mocheso o belang wa metsi ke 100^oC le ka mora ho fihla mochesong wa 100^oMetsi a C ha a sa na liphetoho mochesong empa a fetoha ho tloha mokelikeling ho ea ho khase.

Mekhoeng ea B ho isa ho C, mocheso o monyelang o sebelisoa ho fetola metsi 'ohle hore e be khase. Palo ea mocheso o monyelang e baloa ho sebelisoa mokhoa ona:

Q = m L_V = (2 kg)(2,27 x 10⁶ J/kg) = 4,54 x 10⁶ Lijoule = 4540 x 10³ Lijoule = 4540 lik'hilograma Joule

Karabo e nepahetseng ke B.

11.

Ela hloko kerafo e latelang
Leqhoa le boima ba ligrama tse 50 le futhumatsoa ho tloha ho -5^oho fihlela ho metsi mochesong oa likhato tse 60^oC metsi. Haeba mocheso oa ho kopana ha leqhoa = 80 cal/gram, mocheso o itseng oa leqhoa = 0,5 cal/gram ^oC, mocheso o itseng oa metsi = 1 cal/gram ^oC, joale tekanyo ea mocheso o hlokahalang nakong ea ts'ebetso ho tloha ho C ho ea ho D ke….

A. Likhalori tse 125
B. Likhalori tse 3.000
C. Likhalori tse 4.000
D. Likhalori tse 7.125

Puisano

Hoa tsebahala hore:
Boima ba leqhoa (m es) = 50 grams
Mocheso oa leqhoa (T es) = -5 ^oC
Mocheso o itseng oa leqhoa (c es) = 0,5 cal/gram ^oC
Mocheso oa leqhoa le qhibilihang (leqhoa le lenyenyane) = 80 cal/gram
Mocheso oa metsi (metsi a T) = 60 ^oC
Mocheso o itseng oa metsi (c metsi) = 1 cal/gram ^oC
Potso: Palo ea mocheso ts'ebetsong C ho isa ho D
Karabo:

Mokhoeng oa A ho isa ho B, mocheso oa leqhoa o fetoha ho tloha ho -5 ^oC e ba 0 ^oC
Mokgweng wa B ho isa ho C, leqhoa lohle le fetoha metsi (ntho e tiileng e fetoha mokelikeli). Mokgweng ona, mocheso ha o fetohe.
Ts'ebetsong ea C ho ea ho D, mocheso oa metsi o fetoha ho tloha ho 0 ^oC e ba 60 ^oC

Mocheso o hlokahalang ts'ebetsong ea A ho isa ho B:
Q = mc ΔT
Q = (m_es)(c_es)(0 – T_es)
Q = (50)(0,5)(0-(-5)) = (50)(0,5)(5) = dikhalori tse 125
Mocheso o hlokahalang ts'ebetsong ea B ho isa ho C:
Q = m L
Q = m_es L_es
Q = (50)(80) = dikhalori tse 4000
Mocheso o hlokahalang ts'ebetsong ea C ho isa ho D:
Q = mc ΔT
Q = (m_moya)(c_moya)(T_moya - 0)
Q = (50)(1)(60-0) = (50)(1)(60) = lik'hilojule tse 3000

Mocheso o hlokahalang ts'ebetsong ea A ho isa ho D:
Q = 125 + 4000 + 3000
Q = lik'hilojule tse 7125

Mongoli o bala mocheso o hlokahalang bakeng sa ts'ebetso ka 'ngoe ho u thusa ho utloisisa mokhoa oa ho rarolla bothata ba mofuta ona. Potso ke mocheso o hlokahalang bakeng sa ts'ebetso ea C ho isa ho D.

Karabo e nepahetseng ke B.

12.

Ho ipapisitsoe le kerafo e pela palo ea mocheso Ho hlokahala 3 kg ea leqhoa ts'ebetsong ea ABC ke… (mocheso o itseng es = 2.100 J/kg^oC, mocheso oa ho kopanya es = 336.000 J/kg)

A. 630 kJ
B. 819 kJ
C. 1071 kJ
D. 3276 kJ

Puisano

Kerafo e kaholimo e bontša mokhoa oa ho fetola boemo ba leqhoa ho ba metsi.
Mokgweng wa AB, mocheso o sebediswa ho phahamisa mocheso wa leqhoa ho tloha ho -10^oHo tloha ho C ho isa ho 0^oC.
Q = mc (delta T)
Q = (3)(2100)(0-(-10)) = (3)(2100)(10) = 63.000 Dijoule = 63 kJ (kj = kilo Dijoule)
Mokgweng wa BC, mocheso o sebediswa ho qhibilihisa leqhoa lohle hore e be metsi. Mokgweng ona, mocheso wa leqhoa ha o fetohe.
Q = m L_F
Q = (3)(336.000) = 1.008.000 Li-joule
Palo ea mocheso o hlokahalang bakeng sa leqhoa ts'ebetsong ea ABC ke:
63 kJ + 1.008 kJ = 1071 kJ
Karabo e nepahetseng ke C.

13.

Ela hloko kerafo ea ho futhumatsa ea ligrama tse 500 tsa leqhoa mochesong oa -10^oC ka tlase! Haeba mocheso o itseng oa leqhoa e le 2100 J/kg^oC, mocheso o itseng oa metsi 4.200 J/kg^oC, 'me mocheso oa ho kopana ha leqhoa ke 336.000 J/kg. Ho hlokahala mocheso o mokae bakeng sa ts'ebetso ea BCD?

A. 31.500 J
B. 63.000 J
C. 168.000 J
D. 231.000 J

Puisano
Boima ba leqhoa bo hlahisoa ka ligrama, kahoo bo fetole ho li-kilogram (liyuniti tsa machaba). Ligrama tse 500 = 0,5 kg.
Mokgweng wa BC, mocheso o sebediswa ho qhibilihisa leqhoa lohle hore e be metsi.
Q = m L_F
Q = (0,5)(336.000) = 168.000 Li-joule
Mokhoeng oa CD, mocheso o sebelisoa ho phahamisa mocheso oa metsi ho tloha ho 0^oHo tloha ho C ho isa ho 30^oC
Q = mc (delta T)
Q = (0,5)(4200)(30-0) = (0,5)(4200)(30) = 63.000 Joule
Palo ea mocheso o hlokahalang bakeng sa leqhoa ts'ebetsong ea BCD:
Li-Joule tse 168.000 + Li-Joule tse 63.000 = Li-Joule tse 231.000
Karabo e nepahetseng ke D.

14.
Sheba kerafo ea ho futhumatsa bakeng sa 1 kg ea leqhoa ka tlase! Haeba mocheso o itseng oa leqhoa ke 2.100 J/kg^oC, mocheso oa ho kopana ha leqhoa ke 336.000 J/kg 'me mocheso o itseng oa metsi ke 4.200 J/kg^oC, ebe mocheso o hlokahalang ts'ebetsong ea PQR ke…
A. 10.500 J
B. 21.000 J
C. 336.000 J
D. 346.500 J
Puisano
Mokgweng wa PQ, mocheso o sebediswa ho phahamisa mocheso wa leqhoa ho tloha ho -5^oHo tloha ho C ho isa ho 0^oC
Q = mc (delta T)
Q = (1)(2100)(0-(-5)) = (1)(2100)(5) = 10.500 Joule
Mokgweng wa QR, mocheso o sebediswa ho qhibilihisa leqhoa lohle hore e be metsi.
Q = m L_F
Q = (1)(336.000) = 336.000 Li-joule
Palo ea mocheso o hlokahalang bakeng sa leqhoa ts'ebetsong ea PQR ke:
Li-Joule tse 10.500 + Li-Joule tse 336.000 = Li-Joule tse 346.500
Karabo e nepahetseng ke D.

15. Sheba kerafo ea ho futhumatsa bakeng sa 1 kg ea leqhoa ka tlase!

Haeba mocheso o itseng es 2.100 J/kg^oC, mocheso oa ho kopana ha leqhoa ke 336.000 J/kg 'me mocheso o itseng oa metsi ke 4.200 J/kg^oC, ebe mocheso o hlokahalang ts'ebetsong ea PQR ke…

A. 10.500 J

B. 21.000 J

C. 336.000 J

D. 346.500 J

Puisano

Hoa tsebahala hore:

Boima ba leqhoa = 1 kg

Mocheso oa ho kopana ha leqhoa (L)_F) = 336.000 J/kg

Mocheso o itseng oa leqhoa (c es) = 2.100 J/kg^oC

Mocheso o itseng oa metsi (c metsi) = 4.200 J/kg^oC

O botsitse: Mocheso o hlokahalang ts'ebetsong ea PQR

Karabo:

Mokgweng wa ho tloha ho P ho ya ho Q, mocheso o sebediswa ho phahamisa mocheso wa leqhoa ho tloha ho -5^oC e ba 0^oC. Mocheso o baloa ho sebelisoa mokhoa ona: Q = mc ΔT, moo Q = mocheso, m = boima ba leqhoa, c = mocheso o itseng oa leqhoa, ΔT = phetoho mochesong ho tloha ho -5^oHo tloha ho C ho isa ho 0^oC.

Mocheso o hlokahalang ts'ebetsong ho tloha ho P ho isa ho Q:

Q = mc ΔT = (1)(2100)(0-(-5)) = (2100)(5) = 10500 Dijoule

Mokgweng wa Q ho isa ho R, mocheso o sebediswa ho qhibilihisa leqhoa lohle hore e be metsi. Mokgweng ona, mocheso ha o fetohe. Mocheso o baloa ho sebelisoa foromo: Q = m L_F, moo Q = mocheso, m = boima ba leqhoa, L_F = mocheso oa ho kopana ha leqhoa.

Mocheso o hlokahalang ts'ebetsong Q ho isa ho R:

Q = m L_F = (1)(336.000) = 336.000 Li-joule

Kakaretso ea lik'hilojule:

10500 + 336.000 = 346.500 Joule

Karabo e nepahetseng ke D.

Mohloli oa lipotso:

Lipotso tsa Tlhahlobo ea Naha ea Saense ea Sekolo se Phahameng sa Bana ba Banyenyane/Sekolo se Phahameng sa Boislamo