Zitsanzo 8 za Mafunso Okhudza Kusintha kwa Boma
1. Izi ndi njira yosinthira momwe chinthu chimatulutsa kutentha, makamaka pamene chinthucho...
A. kuzizira ndi kusungunuka
B. kuzizira ndi kuzizira
C. nthunzi ndi kusungunuka
D. kusungunuka ndi kuzizira
Zokambirana
Kusintha kwa momwe zinthu zimatulutsira kutentha ndi:
1. Kuundana (mpweya kukhala madzi), mwachitsanzo nthunzi ya madzi imakhala mame m'mawa.
2. Kuzizira (madzi mpaka olimba), mwachitsanzo madzi amasanduka ayezi.
3. Kusakaniza mpweya kukhala wolimba, mwachitsanzo nthunzi imasanduka chipale chofewa.
Kusintha kwa momwe chinthu chimayamwira kutentha ndi:
1. Kusungunuka/kusungunuka (kolimba mpaka kukhala madzi), mwachitsanzo ayezi wosungunuka
2. Kutuluka kwa nthunzi (madzi kukhala mpweya), mwachitsanzo madzi amatenthedwa kenako nthunzi imasanduka nthunzi
3. Kusanduka kwa mpweya (kolimba kukhala mpweya), mwachitsanzo kusintha kwa camphor kukhala mpweya
Yankho lolondola ndi B.
2. Yang'anani chithunzicho!
Kusintha kwa momwe kutentha kumatulutsira malinga ndi nambala ya chithunzi...
A. 3 ndi 4
B. 2 ndi 4
C. 1 ndi 2
D. 1 ndi 3
Zokambirana
Kusintha kwa momwe zinthu zimatulutsira kutentha ndi:
1. Kuundana (mpweya kukhala madzi), mwachitsanzo nthunzi ya madzi imakhala mame m'mawa.
2. Kuzizira (madzi mpaka olimba), mwachitsanzo madzi amasanduka ayezi.
3. Kusakaniza mpweya kukhala wolimba, mwachitsanzo nthunzi imasanduka chipale chofewa.
Kusintha kwa momwe chinthu chimayamwira kutentha ndi:
1. Kusungunuka/kusungunuka (kolimba mpaka kukhala madzi), mwachitsanzo ayezi wosungunuka
2. Kutuluka kwa nthunzi (madzi kukhala mpweya), mwachitsanzo madzi amatenthedwa kenako nthunzi imasanduka nthunzi
3. Kusanduka kwa mpweya (kolimba kukhala mpweya), mwachitsanzo kusintha kwa camphor kukhala mpweya
Kutengera ndi chithunzichi, nambala 2 = kuzizira (madzimadzi mpaka olimba) ndipo nambala 4 = kuzizira (mpweya mpaka madzi).
Yankho lolondola ndi B.
3. Mafuta a kokonati amatha kuzizira nthawi yozizira. Izi zili choncho chifukwa mafuta a kokonati...
A. nthawi yozizira siilandira kutentha
B. nthawi yozizira pali mphamvu yochuluka ya kutentha
C. imapanga kutentha kochepa kotero imazizira
D. imatulutsa kutentha kwambiri kotero kuti imazizira
Zokambirana
Mafuta a kokonati ndi amadzimadzi, pomwe mafuta a kokonati ozizira ndi olimba. Kusintha kwa momwe mafuta a kokonati amakhalira kuchokera kumadzimadzi kupita ku olimba kumachitika chifukwa chakuti mafuta a kokonati amatulutsa kutentha kwakukulu mumlengalenga wozungulira. Kutulutsa kutentha kumeneku kumachitika chifukwa cha kusiyana kwa kutentha pakati pa mafuta a kokonati ndi mpweya, komwe mafuta a kokonati ndi okwera kuposa mpweya. Zachidziwikire, kutentha kumasamuka kokha kuchokera ku zinthu zomwe zili ndi kutentha kwakukulu kupita ku zomwe zili ndi kutentha kochepa, ndipo kusamutsako kumayima zinthu zonse ziwiri zikafika kutentha komweko.
Yankho lolondola ndi D.
4. Yang'anani chithunzi cha chinthu chotsatirachi!
Makhalidwe enieni a zinthu zomwe zili pachithunzichi ndi...

Zokambirana
Ma ice cubes (chinthu 1) ndi olimba kotero ali ndi voliyumu yokhazikika komanso mawonekedwe okhazikika.
Madzi (chinthu 2) ndi amadzimadzi kotero amakhala ndi voliyumu yokhazikika ndipo amasintha mawonekedwe.
Mpweya (chinthu 3) uli mu mawonekedwe a mpweya kotero umasintha voliyumu ndi mawonekedwe ake.
Yankho lolondola ndi D.
5. Samalani zinthu zomwe zili pachithunzi chotsatira!
Makhalidwe oyenera a zinthu zitatu zomwe zili pachithunzi pamwambapa ndi...

Zokambirana
Chipika chamatabwa (chinthu 1) ndi cholimba kotero chili ndi voliyumu yokhazikika komanso mawonekedwe okhazikika.
Mafuta ophikira (chinthu 2) ndi amadzimadzi kotero amakhala ndi voliyumu yokhazikika ndipo amasintha mawonekedwe.
Mitambo (chinthu 3) ili mu mawonekedwe a mpweya kotero imakhala ndi voliyumu yosinthasintha komanso mawonekedwe osinthika.
Yankho lolondola ndi C.
6. Yang'anani chithunzicho!
Mawu olondola okhudza mtundu wa chinthucho malinga ndi chithunzicho akuwonetsedwa ndi...
Zokambirana
Utsi (chinthu 1) uli mu mawonekedwe a mpweya kotero umasintha voliyumu ndi mawonekedwe.
Madzi (chinthu 2) ndi amadzimadzi kotero amakhala ndi voliyumu yokhazikika ndipo amasintha mawonekedwe.
Galasi (chinthu 3) ndi lolimba kotero lili ndi voliyumu yokhazikika komanso mawonekedwe okhazikika.
Yankho lolondola ndi D.
7. (1) voliyumu yokhazikika
(2) kakonzedwe ka tinthu tating'onoting'ono tokhazikika
(3) mphamvu yokoka pakati pa tinthu tating'onoting'ono ndi yamphamvu
(4) kusintha kwa mawonekedwe
(5) mtunda pakati pa tinthu tating'onoting'ono ndi waukulu kwambiri
Kutengera ndi deta iyi, makhalidwe a zakumwa amasonyezedwa ndi nambala...
A. (1), (2), ndi (3)
B. (1), (4), ndi (5)
C. (2), (3), ndi (4)
D. (2), (4), ndi (5)
Zokambirana
(1) zinthu zolimba ndi zamadzimadzi
(2) zinthu zolimba
(3) zinthu zolimba
(4) madzi
(5) madzi
Yankho lolondola ndi B.
8.
Samalani ndi graph yotsatirayi
Ice lolemera magalamu 50 limatenthedwa kuyambira -5oC mpaka madzi pa kutentha kwa madigiri 60oMadzi a C. Ngati kutentha kwa ayezi = 80 cal/gram, kutentha kwa ayezi = 0,5 cal/gram oC, kutentha kwa madzi = 1 cal/gramu oC, ndiye kuti kuchuluka kwa kutentha komwe kumafunika panthawiyi kuyambira C mpaka D ndi….
A. Ma calories 125
B. Ma calories 3.000
C. Ma calories 4.000
D. 7.125 calories
Zokambirana
Amadziwika kuti:
Unyinji wa ayezi (m es) = 50 magalamu
Kutentha kwa ayezi (T es) = -5 oC
Kutentha kwa ayezi (c es) = 0,5 cal/gram oC
Kutentha kwa ayezi wosungunuka (L ayezi) = 80 cal/gram
Kutentha kwa madzi (madzi a T) = 60 oC
Kutentha kwa madzi (c madzi) = 1 cal/gramu oC
Funso: Kuchuluka kwa kutentha mu ndondomeko C mpaka D
Yankho:
Mu ndondomeko A mpaka B, kutentha kwa ayezi kumasintha kuchokera pa -5 oC ikukhala 0 oC
Mu ndondomeko B mpaka C, ayezi onse amasanduka madzi (cholimba chimasanduka madzi). Mu ndondomekoyi, kutentha sikusintha.
Mu ndondomeko C kupita ku D, kutentha kwa madzi kumasintha kuchokera pa 0 oC ikukhala 60 oC
Kutentha komwe kumafunika mu ndondomeko A mpaka B:
Q = mc ΔT
Q = (mes)(ces)(0 – Tes)
Q = (50)(0,5)(0-(-5)) = (50)(0,5)(5) = ma calories 125
Kutentha komwe kumafunika mu ndondomeko B mpaka C:
Q = m L
Q = mes Les
Q = (50)(80) = ma calories 4000
Kutentha komwe kumafunika mu ndondomeko C mpaka D:
Q = mc ΔT
Q = (mmpweya)(cmpweya)(Tmpweya - 0)
Q = (50)(1)(60-0) = (50)(1)(60) = ma calories 3000
Kutentha komwe kumafunika mu ndondomeko A mpaka D:
Q = 125 + 4000 + 3000
Q = ma calories 7125
Wolembayo amawerengera kuchuluka kwa kutentha komwe kumafunika pa njira iliyonse kuti akuthandizeni kumvetsetsa momwe mungathetsere vutoli lamtunduwu. Funso ndi kutentha komwe kumafunika pa njira C mpaka D.
Yankho lolondola ndi B.
9. Yang'anani chithunzi cha chinthu chotsatirachi!
Makhalidwe enieni a zinthu zomwe zili pachithunzichi ndi...

Zokambirana
Ma ice cubes (chinthu 1) ndi olimba kotero ali ndi voliyumu yokhazikika komanso mawonekedwe okhazikika.
Madzi (chinthu 2) ndi amadzimadzi kotero amakhala ndi voliyumu yokhazikika ndipo amasintha mawonekedwe.
Mpweya (chinthu 3) uli mu mawonekedwe a mpweya kotero umasintha voliyumu ndi mawonekedwe ake.
Yankho lolondola ndi D.
10. Samalani zinthu zomwe zili pachithunzi chotsatira!
Makhalidwe oyenera a zinthu zitatu zomwe zili pachithunzi pamwambapa ndi...

Zokambirana
Chipika chamatabwa (chinthu 1) ndi cholimba kotero chili ndi voliyumu yokhazikika komanso mawonekedwe okhazikika.
Mafuta ophikira (chinthu 2) ndi amadzimadzi kotero amakhala ndi voliyumu yokhazikika ndipo amasintha mawonekedwe.
Mitambo (chinthu 3) ili mu mawonekedwe a mpweya kotero imakhala ndi voliyumu yosinthasintha komanso mawonekedwe osinthika.
Yankho lolondola ndi C.
11. Yang'anani chithunzicho!
Mawu olondola okhudza mtundu wa chinthucho malinga ndi chithunzicho akuwonetsedwa ndi...
Zokambirana
Utsi (chinthu 1) uli mu mawonekedwe a mpweya kotero umasintha voliyumu ndi mawonekedwe.
Madzi (chinthu 2) ndi amadzimadzi kotero amakhala ndi voliyumu yokhazikika ndipo amasintha mawonekedwe.
Galasi (chinthu 3) ndi lolimba kotero lili ndi voliyumu yokhazikika komanso mawonekedwe okhazikika.
Yankho lolondola ndi D.
12. Samalani ndi makhalidwe a zinthu zotsatirazi!
(1) voliyumu yokhazikika
(2) kakonzedwe ka tinthu tating'onoting'ono tokhazikika
(3) mphamvu yokoka pakati pa tinthu tating'onoting'ono ndi yamphamvu
(4) kusintha kwa mawonekedwe
(5) mtunda pakati pa tinthu tating'onoting'ono ndi waukulu kwambiri
Kutengera ndi deta iyi, makhalidwe a zakumwa amasonyezedwa ndi nambala...
A. (1), (2), ndi (3)
B. (1), (4), ndi (5)
C. (2), (3), ndi (4)
D. (2), (4), ndi (5)
Zokambirana
(1) zinthu zolimba ndi zamadzimadzi
(2) zinthu zolimba
(3) zinthu zolimba
(4) madzi
(5) madzi
Yankho lolondola ndi B.
Gwero la funso:
Mafunso a Mayeso a Sayansi ya Sukulu ya Sekondale/Chisilamu cha Sukulu ya Sekondale