Uma izinto ezinamazinga okushisa ahlukene zihlangana, ukushisa ngokwemvelo kuhamba kusuka entweni enezinga lokushisa eliphakeme kuya entweni enezinga lokushisa eliphansi. Ukudluliselwa kokushisa kuyama uma izinto ezimbili zifinyelela ukulingana kokushisa . Kungashiwo ukuthi ukudluliselwa kokushisa kubangela ushintsho ekushiseni kwezinto ezixhumanayo. Ngokusekelwe kule ncazelo emfushane, kuphethwa ngokuthi ukushisa (Q) kuhlobene nento kanye noshintsho lokushisa (delta T) yaleyo nto. Into ngayinye inesisindo (m) futhi uhlobo lwento nalo luhlukile.
Ukutholwa kwefomula yokushisa kulesi sihloko kwenziwa ngokucabanga. Ungafakazela ubuqiniso balokhu kucabanga ngokusekelwe kokuhlangenwe nakho kwakho kwansuku zonke noma ngokwenza ucwaningo.
Ubudlelwano phakathi kokushisa (Q) nokushintsha kwezinga lokushisa (delta T)
Kunezitsha ezimbili ezigcwele amanzi anobunzima obufanayo. Amanzi afudunyezwa kusetshenziswa izitsha ezimbili ezahlukene. Ilangabi elisesitsheni esisodwa liphansi, kanti ilangabi elisesitsheni esinye liphakeme. Uma zombili zifudunyezwa imizuzu eyishumi, yisiphi isitsha esishisa kakhulu? Uma wake wafudumeza amanzi, uzovuma ukuthi amanzi afudunyezwa kusetshenziswa isitofu esinomlilo ophezulu ashisa kakhulu (izinga lokushisa lokugcina lamanzi liphakeme noma ushintsho lokushisa lukhulu).
Ilangabi limelela inani lokushisa (Q). Ilangabi elincane linokushisa okuncane, ilangabi elikhulu linokushisa okwengeziwe. Uma kunokushisa okuncane, ushintsho lokushisa luncane. Uma kunokushisa okuningi, ushintsho lokushisa lukhulu. Uma ukushisa okuningi, ushintsho lokushisa lukhulu. Kungaphethwa ngokuthi inani lokushisa (Q) lilingana noshintsho lokushisa lento.
Ubudlelwano phakathi ukushisa (Q) kanye nesisindo sento (m)
Kunezitsha ezimbili ezigcwele amanzi anezinqwaba ezahlukene, esinye sigcwele amanzi amaningi, esinye sigcwele amanzi amancane. Amanzi afudunyezwa kusetshenziswa izitofu ezimbili ezinelangabi elifanayo. Uma zombili zifudunyezwa imizuzu eyishumi, yimaphi amanzi asesitsheni ashisa kakhulu? Uma wake wafudumeza amanzi uzovuma ukuthi amanzi emanzini amancane ashisa kakhulu (izinga lokushisa lokugcina lamanzi likhulu noma ushintsho lokushisa lukhulu). Ukuze amanzi amaningi abhekane noshintsho lokushisa olufanayo namanzi amancane, ilangabi elifudumeza amanzi amaningi kumele likhuliswe.
Inani lamanzi limelela isisindo samanzi (m). Ubukhulu belangabi bumelela inani lokushisa. Kungaphethwa ngokuthi inani lokushisa (Q) lihambisana nokushintsha kwezinga lokushisa lento. Uma amanzi emaningi, kudingeka ukushisa okwengeziwe ukuze kukhushulwe izinga lokushisa lamanzi.
Ubudlelwano phakathi kokushisa (Q) nohlobo lwento ( c )
Uma ufudumeza insimbi kanye nengilazi yobukhulu obufanayo ngesikhathi esisodwa usebenzisa ilangabi elifanayo, yiliphi elizoshisa ngokushesha, insimbi noma ingilazi? Yiqiniso, insimbi izoshisa ngokushesha. Kungaphethwa ngokuthi ukushisa okudingekayo ukuphakamisa izinga lokushisa lento kuhambisana nohlobo lwento.
Ukuqhathanisa okuthathu okungenhla kuhlanganiswe kwaba yi-equation:
Lena ifomula noma i-equation yokushisa.
Ulwazi: Q = ukushisa (iJoule), m = isisindo sento (kg), c = ukushisa okuthile kwento (J/kg Co), i-delta T = ushintsho lokushisa (Co noma K)
1. Amakhilogremu amahlanu eqhwa ekushiseni okungu--22 oC ayashiswa kuze kube yilapho lonke iqhwa lincibilika ekushiseni okungu-0 oC . Uma ukushisa okucashile kweqhwa kungu-333 kJ/kg kanti ukushisa okukhethekile kweqhwa kungu-2100 J/kg C , khona-ke inani lokushisa elidingekayo...
A. 1496 kJ
B. 1596 kJ
C. 1696 kJ
D. 1796 kJ
E. 1896 kJ
Ingxoxo
Kuyaziwa:
Isisindo seqhwa (m) = 5 kg
Izinga lokushisa lokuqala (T) = -22 o C
Ukushisa okucashile kweqhwa (L) = 333 kJ/kg = 333.000 J/kg
Ukushisa okuqondile kweqhwa (c) = 2100 J/kg C o
Umbuzo: Inani lokushisa elidingekayo (Q)
Impendulo:
Inqubo 1: khulisa izinga lokushisa leqhwa kusuka ku--22 o C kuya ku-0 o C
Q = mc ΔT = (5)(2100)(22) = 231.000 amaJoules
Inqubo 2: ncibilikisa lonke iqhwa emanzini
Q = m L = (5)(333.000) = 1.665.000 J
Ukushisa okuphelele = 231.000 J + 1.665.000 J = 1.896.000 J = 1.896 kJ
Impendulo efanele ngu-E.
Umthombo wombuzo:
Imibuzo yeFiziksi ye-SBMPTN
