Incazelo yesihloko sokushisa Okulingana nokushisa komshini Isilinganiso sokushisa
1. Incazelo yokushisa
Uma izinto ezinomehluko wokushisa zithintana, kuzoba nokudluliselwa kokushisa kusuka ezintweni ezinokushisa okuphezulu kuya ezintweni ezinokushisa okuphansi. Ukudluliselwa kokushisa kuyama ngemva kokuthinta izinto kufinyelela izinga lokushisa elifanayo. Isibonelo, uma sixuba amanzi ashisayo namanzi abandayo, ukushisa kuvame ukuhamba kusuka emanzini ashisayo kuya emanzini abandayo. Uma sifaka insimbi eshisayo emanzini abandayo, ukushisa kuhamba kusuka ensimbini kuya emanzini. Ukushisa kuzoyeka ukugeleza ngemva kokuba insimbi namanzi kufinyelele izinga lokushisa elifanayo. Lapho umhlengikazi enamathisela i-thermometer emzimbeni wakho, ukushisa kuhamba kusuka
umzimba wakho uya ku-thermometer. Ukudluliselwa kokushisa kuyama uma umzimba wakho kanye ne-thermometer sekufinyelele izinga lokushisa elifanayo. Uma i-thermometer esetshenziswayo kuyi-thermometer ye-mercury, lapho umzimba wakho kanye ne-thermometer kufinyelela izinga lokushisa elifanayo, ubuso be-mercury buyayeka ukunyakaza. Inombolo ekhonjisiwe ebusweni be-mercury izinga lokushisa lomzimba wakho ngaleso sikhathi.
Ngokwemvelo, ukushisa kuhamba ngokuzenzakalelayo kusuka ezintweni ezishisa kakhulu kuya
Izinto ezinokushisa okuphansi. Ukudluliselwa kokushisa kuvame ukulinganisa izinga lokushisa lezinto ezithintanayo. Ngekhulu le-18, izazi zefiziksi zazisola ukuthi ukugeleza kokushisa kwakuwukuhamba koketshezi, uhlobo loketshezi olwalungabonakali (uketshezi luyinto engageleza. Uketshezi luhlanganisa izinto eziwuketshezi nezigesi. Amanzi (uketshezi) ahlanganisa uketshezi ngoba lungageleza. Umoya nawo uhlanganisa uketshezi ngoba lungageleza). Uketshezi lubizwa ngokuthi ama-caloric. Inkolelo-mbono yama-calories ayisasetshenziswa ngoba ngokusekelwe emiphumeleni yokuhlolwa, ukuba khona kwala ma-calories akunakufakazelwa. Ngekhulu le-19, isazi sefiziksi saseNgilandi ogama lakhe linguJames Prescott Joule (1818-1889) safunda indlela yokushisa amanzi esitsheni sisebenzisa isondo elishukumisayo.
Ngokusekelwe emiphumeleni yokuhlolwa, uJoule wenza ukuqhathanisa namanzi ashisayo esebenzisa umlilo. Lapho ilangabi nesitsha esinamanzi sithintana, ukushisa kuhamba kusuka emlilweni (izinga lokushisa eliphezulu) kuya emanzini (izinga lokushisa eliphansi). Ngemva kokuqhathanisa phakathi kokushisa kwamanzi okukhuphukayo ngenxa yokuthintana nomlilo kanye nokushisa kwamanzi okukhuphukayo ngenxa yomsebenzi owenziwe yi-stirrer, uJoule waphetha ngokuthi ukushisa amandla ahamba esuka entweni enokushisa okuphezulu aye entweni enokushisa okuphansi. Ukushisa akuwona amandla (ukushisa akulona uhlobo oluthile lwamandla, njengamandla e-kinetic, amandla angase abe khona, amandla amakhemikhali, njll.). Ukushisa kungamandla ahambayo ngenxa yokwehluka kwezinga lokushisa. Ngakho-ke, lapho ukushisa kugeleza kusuka ezintweni ezinokushisa okuphezulu kuya ezintweni ezinokushisa okuphansi, amandla ahamba kusuka ezintweni ezinokushisa okuphezulu aye ezintweni ezinokushisa okuphansi. Ukudluliswa kwamandla kuyama ngemva kokuthinta izinto kufinyelela izinga lokushisa elifanayo.
2. Iyunithi yokushisa kanye nokushisa okulingana nomshini
Amayunithi okushisa angama-calories (afingqiwe ngokuthi ama-cal). Ama-calories yinani lokushisa elidingekayo ukuphakamisa izinga lokushisa le-1 gram yamanzi ngo-1 C.o (ngokuqondile, kusukela ku-14.5 oC kuya ku-15.5 oC). Inani lokushisa elidingekayo liyahlukahluka ngokushisa kwamanzi ahlukene. Ngenani elifanayo lokushisa, izinga lokushisa lamanzi liyakhuphuka ngo-1 Co kwenzeka kuphela phakathi kwamazinga okushisa angu-14.5 oC kuya ku-15.5 oC. Amayunithi okushisa avame ukusetshenziswa, ikakhulukazi ukusho ukuthi inani lamandla okudla lingama-kilocalories (kcal). 1 kcal = amakhalori ayi-1000. Amanye amagama avela ku-1 kcal = 1 Ikhalori (uhlamvu olukhulu lwe-K). Iyunithi yokushisa yesistimu yaseBrithani yi-Btu (iyunithi yokushisa yaseBrithani). 1 Btu = inani lokushisa elidingekayo ukuphakamisa izinga lokushisa le-1 pound (0.45 kg) lamanzi ngo-1 Fo (Kusukela ngqo ku-63 oF kuye ku-64 oF).
Ukushisa kuhlobene namandla, ngakho-ke sidinga ukwazi ubudlelwano phakathi kwamayunithi okushisa namayunithi wamandla. Ngokusekelwe ekuhlolweni okwenziwe nguJoule nabanye ososayensi, kwaziwa ukuthi umsebenzi wamaJoule angu-4.186 ulingana nekhalori elilodwa lokushisa.
Ikhalori eli-1 = 4.186 Joule
1 kcal = amakhalori ayi-1000 = ama-Joules angu-4186
I-Btu eyi-1 = 778 ft (0.24 km). lb = amakhalori angu-252 = 1055 Joules
(Ikhalori eli-1 = 4.186 Joule kanye ne-1 kcal = 4186 ebizwa ngokuthi okulingana nokushisa ngomshini)
3. Isibalo sokushisa
Uma izinto ezinomehluko wokushisa zithintana, ngokwemvelo, ukushisa kuhamba kusuka ezintweni ezinokushisa okuphezulu kuya ezintweni ezinokushisa okuphansi. Ukudluliselwa kokushisa kuyama ngemva kokuba zombili izinto sezisesimweni sokulingana kokushisa. Ukudluliselwa kokushisa kubangela izinguquko ekushiseni kwezinto ezithintana. Ngokusekelwe kule ncazelo emfushane, ungaphetha ngokuthi ukushisa (Q) kunobuhlobo nento kanye noshintsho ekushiseni (ΔT) kwento, isisindo sento (m) kanye nohlobo lwento.
Ubudlelwano phakathi kokushisa (Q) nokushintsha kwezinga lokushisa (ΔT)
Uma ukushisa kukhulu, kulapho izinga lokushisa lishintsha khona kakhulu. Kungaphethwa ngokuthi inani lokushisa (Q) lilingana nokushintsha kwezinga lokushisa lento.
Q α ΔT —– Ukuqhathanisa 1
Ubudlelwano phakathi kokushisa (Q) kanye nesisindo sezinto (m)
Inani lokushisa (Q) lihambisana nokushintsha kwezinga lokushisa lento. Uma amanzi amaningi, kulapho kudingeka khona ukushisa okwengeziwe ukuze kwandiswe izinga lokushisa lamanzi.
Q α m —– Ukuqhathanisa 2
Ubudlelwano phakathi kokushisa (Q) nohlobo lwento (c)
Ukushisa okudingekayo ukuze kukhushulwe izinga lokushisa lento kuhambisana nohlobo lwento.
Q α c —– Ukuqhathanisa 3
Ukuqhathaniswa okuthathu okungenhla kuhlanganiswa ndawonye kube yi-equation:
Q α mc ΔT
Q = mc ΔT
Lesi yisibalo sokushisa.
Incazelo: Q = ukushisa (Joule), m = isisindo sento (kg), c = ukushisa okuthile (J / kg C o noma K)
