Zafi da canjin lokaci - matsaloli da mafita
1. Dangane da jadawalin, menene zafin da ruwa mai nauyin kilogiram 5 ke sha yayin aikin CD? Takamaiman zafin ruwa = 4,200 J/kg o C.
An sani:
Nauyi (m) = 5 kg
Takamaiman zafin ruwa (c) = 4200 J/kg o C
Zafin farko (T1 ) = 0 oC
Zafin ƙarshe (T2 ) = 10 oC
Sauyin yanayin zafi (ΔT) = 10 o C – 0 o C = 10 o C
Ana so: Zafi (Q)
Magani:
Q = mc ΔT = (5 kg)(4200 J/kg o C)(10 o C) = (5)(4200 J)(10) = (50)(4200 J) = 210,000 Joules
2. Menene zafin da gram 20 na kankara ke sha yayin aikin AC, idan takamaiman zafin kankara shine 2100 J/kg o C kuma zafin haɗa kankara shine 336,000 J/kg.
An sani:
Nauyin kankara (m) = gram 200 = kilogiram 200/1000 = kilogiram 0.2
Takamaiman zafi (c) = 2100 J/kg o C
Zafin haɗewar kankara (L F ) = 336,000 J/kg
Ana so: Zafin da kankara ke sha yayin aikin AC
Magani:
A lokacin aikin AB, kankara tana sha zafi don canza zafinsa daga -10 oC zuwa 0 oC.
Q = mc ΔT
Q = zafi, m = yawan kankara, c = takamaiman zafin kankara, ΔT = canjin zafin jiki
Q 1 = mc ΔT = (0.2)(2100)(0-(-10) = (0.2)(2100)(10) = (2)(2100) = Joules 4200
A lokacin aikin BC, ana sha zafi don narke dukkan kankara zuwa ruwa. A cikin wannan tsari yana canzawa ne kawai a mataki kuma babu canjin zafin jiki. Kankara da ruwan zafinsu ya kasance 0 oC.
Zafi da aka sha yayin aiwatar BC:
Q2 = m L F = (0.2 kg)(336,000 J/kg) = Joules 67,200
Zafi da ake sha yayin aikin AC:
Q = Q 1 + Q 2 = 4200 Joules + 67,200 Joules = 71,400 Joules
3. Ana dumama ruwa mai nauyin kilogiram 2, kuma zafin tururi don ruwa = 2.27 x 10 6 J/kg, takamaiman zafi don ruwa = 4,200 J/kg o C kuma matsin lamba na yanayi shine 1 atm, menene zafin da ruwa ke sha yayin aikin BC?
An sani:
Nauyi (m) = 2 kg
Zafin tururin ruwa (L V ) = 2.27 x 10 6 J/kg
Takamaiman zafi ga ruwa (c) = 4,200 J/kg o C
Ana so: Zafi yana sha yayin aikin BC.
Magani:
A cikin aikin AB, ana sha zafi don ƙara zafin ruwa daga 60 oC zuwa 100 oC.
Q = m L V = (2 kg)(2.27 x 10 6 J/kg) = 4.54 x 10 Joules 6 = 4540 x 10 Joules 3 = Joules 4540
4. Dangane da hoton da ke ƙasa, idan nauyin kankara ya kai gram 500, takamaiman zafi shine 2100 J/kg o C kuma zafin da ke ɓoye na haɗuwar kankara shine 336,000 J/kg. Kayyade zafin da ake buƙata a cikin tsari na P–Q–R.
An sani:
Nauyin kankara (m) = gram 500 = 500/1000 kg = 0.5 kg
Takamaiman zafi ga kankara (c) = 2100 J/kg o C
Zafin haɗuwa mai ɓoye (L F ) = 336,000 J/kg
Ana so: Zafi
Magani:
Tsarin PQ = zafi da ake sha don ɗaga zafin kankara daga -4 o C zuwa 0 o C
Tsarin QR = zafi da kankara ke sha don narke dukkan kankara zuwa ruwa
An ƙididdige zafi da aka sha yayin aiki ta amfani da lissafi:
Q = mc ΔT
Q = zafi, m = taro, c = takamaiman zafin kankara, ΔT = canjin zafin jiki
Ana ƙididdige kankara da zafi yayin aiwatar da PQ ta amfani da wannan lissafin:
Q = (0.5 kg) (2100 J/kg o C) (0 o C (-4 o C))
Q = (0.5kg)(2100 J/kg o C)(0 o C + 4 o C)
Q = (0.5 kg) (2100 J/kg o C) (4 o C)
Q = (0.5)(2100 J)(4)
Q = Joules 4200
An ƙididdige zafi da aka sha yayin aiki ta amfani da wannan lissafin QR:
Q = m L F
Q = (0.5 kg)(336,000 J/kg)
Q = (0.5)(336,000 J)
Q = Joules 168,000
Jimlar zafi:
Q = Joules 4200 + Joules 168,000
Q = Joules 172,200
Q = 172.2 kilogiram na Joule
Q = 172.2 kJ
5. Kankara mai nauyin gram 50 da aka dumama daga -5 oC zuwa ruwa a zafin jiki na 60 oC . Idan zafin da aka haɗa kankara shine 80 cal/gram, zafin da aka ƙayyade wa kankara shine 0.5 cal/gram oC , zafin da aka ƙayyade wa ruwa shine 1 cal/gram oC , ƙayyade zafin da ake buƙata a cikin CD ɗin sarrafawa.
An sani:
Nauyin kankara = nauyin ruwa (m) = gram 50 
Zafin da ke ɓoye na haɗuwar kankara (LF ) = 80 cals/gram
Takamaiman zafi ga kankara (c kankara) = 0.5 cal/gram o C
Takamaiman zafi ga ruwa (c ruwa) = 1 cal/gram o C
Ana so: Ana buƙatar zafi a cikin CD ɗin aiki
Magani:
A cikin tsari na A zuwa B, ana amfani da zafi don ɗaga zafin kankara daga -5 o C zuwa 0 o C. Ana ƙididdige zafi ta amfani da wannan lissafi: Q = mc ΔT, inda Q = zafi, m = yawan kankara, c = takamaiman zafi don kankara, ΔT = canjin zafin jiki daga -5 o C zuwa 0 o C.
A cikin tsari na B zuwa C, ana amfani da zafi don narke dukkan kankara zuwa ruwa. A cikin wannan tsari, ba a canza zafin jiki ba. An ƙididdige zafi ta amfani da wannan lissafi: Q = m L F , inda Q = zafi, m = yawan kankara, L F = zafi mai ɓoye na haɗuwar kankara.
A cikin tsari C zuwa D, ana amfani da zafi don ɗaga zafin ruwa daga 0 o C zuwa 60 o C. Ana ƙididdige zafi ta amfani da wannan lissafi: Q = mc ΔT, inda Q = zafi, m = yawan ruwa, c = takamaiman zafin ruwa, ΔT = canjin zafin jiki daga 0 o C zuwa 60 o C.
Zafin da ake buƙata daga tsari C zuwa D:
Q = mc ΔT = (gram 50)(cal 1/gram o C)(60 o C-0 o C) = (50)(1)(60) cal = 3000 cal
6. Idan nauyin kankara ya kai kilogiram 1, takamaiman zafin kankara shine 2100 J/kg o C, zafin da ke ɓoye na haɗa kankara shine 336,000 J/kg kuma takamaiman zafin ruwa shine 4200 J/kg o C, to sai a tantance zafin da ake buƙata a cikin PQR.
An sani:
Nauyin kankara = 1 kg
Zafin da ke ɓoye na haɗewar kankara (L F ) = 336,000 J/kg
Takamaiman zafin kankara (c kankara) = 2,100 J/kg o C
Takamaiman zafin ruwa (c ruwa) = 4,200 J/kg o C
Ana so: Ana buƙatar zafi a cikin tsari PQR
Magani:
A cikin tsari na P zuwa Q, ana amfani da zafi don ɗaga zafin kankara daga -5 o C zuwa 0 o C. Ana ƙididdige zafi ta amfani da wannan lissafi: Q = mc ΔT, inda Q = zafi , m = yawan kankara , c = takamaiman zafin kankara, ΔT = canjin zafin jiki daga -5 o C zuwa 0 o C.
Zafin da ake buƙata a cikin tsari P zuwa Q:
Q = mc ΔT = (1)(2100)(0-(-5)) = (2100)(5) = Joules 10500
A cikin tsari na Q zuwa R, zafin da ake buƙata don narke dukkan kankara zuwa ruwa. A cikin wannan tsari, zafin ba ya canzawa. An ƙididdige zafi ta amfani da wannan lissafi: Q = m L F , inda Q = zafi , m = yawan kankara , L F = zafi mai ɓoye na haɗuwar kankara.
Zafin da ake buƙata a cikin tsari Q zuwa R:
Q = m L F = (1) (336,000) = 336,000 Joules
Jimlar zafi:
10,500 + 336,000 = Joules 346,500
- Menene zafi a ɓoye?
- Amsa: Zafi mai ɓoyewa shine kuzarin zafi da ake buƙata don canza yanayin wani abu ba tare da canza zafinsa ba. Yana wakiltar kuzarin da ake buƙata don karya ko samar da haɗin gwiwa tsakanin ƙwayoyin halitta yayin canje-canjen lokaci.
- Me yasa zafin jiki yake tsayawa a lokacin canjin lokaci?
- Amsa: A lokacin canjin lokaci, duk wani makamashin zafi da aka bayar ko aka cire ana amfani da shi ne don canza yanayin sinadarin. Ana amfani da wannan makamashin ne don karya ko samar da haɗin gwiwa tsakanin ƙwayoyin halitta, ba don ƙara kuzarin motsi ko zafin jiki na sinadarin ba.
- Menene bambanci tsakanin zafin da ke ɓoye na haɗuwa da zafin da ke ɓoye na vaporization?
- Amsa: Zafin haɗuwar da ke ɓoye yana nufin ƙarfin zafi da ake buƙata don canza abu daga daskararre zuwa ruwa (ko akasin haka) a lokacin narkewarsa. Zafin tururi yana nufin ƙarfin zafi da ake buƙata don canza abu daga ruwa zuwa iskar gas (ko akasin haka) a lokacin tafasarsa.
- Me yasa muke jin sanyi idan muka fito daga wurin wanka a ranar da iska ke kadawa, koda kuwa yanayin zafi na iska yana da dumi?
- Amsa: Yayin da ruwa ke ƙafewa daga fatarmu, yana fuskantar canjin lokaci daga ruwa zuwa tururi. Wannan tsari yana buƙatar kuzari, wanda ake ɗauka daga fatarmu a cikin yanayin zafi, wanda ke sa fatarmu ta ji sanyi.
- Me yasa tururin da ke zafi a digiri 100 ya fi hatsari fiye da ruwan zafi a digiri 100?
- AmsaTururi yana ɗauke da makamashi fiye da ruwan tafasa saboda ya sha zafi mai ɓoye na tururi a lokacin canjin lokaci daga ruwa zuwa tururi. Lokacin da tururi ya taru a fata, yana fitar da wannan ƙarin kuzarin, yana haifar da ƙonewa mai tsanani fiye da ruwan tafasa.
- Ta yaya ƙara gishiri a kan kankara ke rage zafin narkewarsa?
- Amsa: Ƙara gishiri yana kawo cikas ga daidaito tsakanin narkewar da daskarewar cakuda ruwan ƙanƙara. Wannan yana sa ƙanƙara ta narke a ƙaramin zafin jiki fiye da yadda aka saba, wanda hakan ke rage yawan daskarewar cakuda.
- Me yasa gumi ke taimakawa wajen sanyaya jiki a rana mai zafi?
- Amsa: Gumi, idan ya ƙafe daga fata, yana canzawa daga ruwa zuwa iskar gas. Wannan tsari na ƙafewa yana buƙatar kuzari, wanda ake ɗauka daga fata, don haka yana sanyaya ta.
- Mene ne sublimation a cikin mahallin canje-canje na lokaci?
- Amsa: Sublimation shine canjin yanayin kai tsaye daga daskararre zuwa iskar gas ba tare da ya ratsa ta cikin yanayin ruwa ba. Misali gama gari shine busasshen kankara (daskararrewar carbon dioxide) wanda ke canzawa kai tsaye zuwa iskar carbon dioxide.
- Me yasa ake buƙatar makamashin zafi don narke kankara duk da cewa zafin yana nan a 0°C?
- Amsa: Ana amfani da makamashin zafi don karya haɗin da ke riƙe da kankara a cikin tsarinta mai ƙarfi. Da zarar waɗannan haɗin sun karye, kankarar za ta koma matakin ruwa, duk da cewa babu canjin zafin jiki.
- Ta yaya matsin lamba ke shafar wurin tafasar ruwa?
- Amsa: Gabaɗaya, ƙara matsin lamba na waje yana ɗaga tafasar ruwa, yayin da rage matsin lamba ke rage tafasar. Wannan shine dalilin da ya sa ruwa ke tafasa a yanayin zafi ƙasa da 100°C a wurare masu tsayi, inda matsin lamba na yanayi yake ƙasa.
