Lub peev xwm ua kom sov ntsuas lub zog uas xav tau ntxiv rau ib qho khoom ua kom sov dua ib qib. Lub peev xwm cua sov ntawm ib yam khoom tau pom siv cov qauv yooj yim - los ntawm kev faib cov cua sov uas tau muab los ntawm kev hloov pauv kub kom txiav txim siab qhov xav tau ntawm lub zog xav tau hauv ib qib. Txhua yam khoom siv hauv ntiaj teb no muaj peev xwm sib txawv cua sov. (Tau qhov twg los: Hoob 10 Phau Ntawv Txuj Ci Physics)
Cov mis: Muaj Peev Xwm Thaum Tshav Kub = (Muab Lub Zog Kub) / (Ua Kom Kub Ntxiv)
Kauj ruam
Txoj Kev 1 ntawm 2: Xam Lub Peev Xwm Kub Kub ntawm Lub Hom Phiaj
Kauj Ruam 1. Paub cov mis kom muaj peev xwm ua kom sov
Lub peev xwm cua sov ntawm ib yam khoom tuaj yeem suav los ntawm kev faib cov cua sov uas tau muab (E) los ntawm kev hloov pauv kub (T). Qhov sib npaug yog: Muaj peev xwm ua kom sov = E/T.
- Piv txwv: Lub zog xav tau kom sov lub thaiv kom 5 degrees Celsius yog 2000 Joules - lub peev xwm ua kom sov ntawm lub thaiv yog dab tsi?
- Muaj peev xwm ua kom sov = E/T.
- Muaj peev xwm ua kom sov = 2000 Joule / 5˚C
- Cov cua sov muaj peev xwm = 400 Joules per degree Celsius (J/˚C)
Kauj Ruam 2. Saib qhov hloov pauv kub
Piv txwv li, yog tias kuv xav paub lub peev xwm ua kom sov ntawm lub thaiv, thiab kuv paub tias nws siv 60 Joules txhawm rau nce qhov kub ntawm qhov thaiv los ntawm 8 degrees txog 20 degrees, Kuv yuav tsum paub qhov sib txawv ntawm ob qhov kub kom tau txais cua sov. peev xwm. Txij li 20 - 8 = 12, qhov ntsuas kub ntawm qhov hloov pauv 12 degrees. Yog li ntawd:
- Muaj peev xwm ua kom sov = E/T.
- Lub peev xwm cua sov ntawm qhov thaiv = 60 Joules / (20˚C - 8˚C)
- 60 Joule / 12˚C
- Lub peev xwm cua sov ntawm qhov thaiv = 5 J/˚C
Kauj Ruam 3. Ntxiv cov chav kom raug rau koj cov lus teb kom muab lub ntsiab lus
Lub peev xwm cua sov ntawm 300 txhais tau tias tsis muaj dab tsi yog tias koj tsis paub yuav ntsuas nws li cas. Lub peev xwm cua sov yog ntsuas los ntawm lub zog xav tau ib qib. Yog li, yog tias peb ntsuas lub zog hauv Joules, thiab hloov pauv kub hauv Celsius, cov lus teb kawg yuav yog pes tsawg Joules xav tau ib qib Celsius. Yog li, peb yuav nthuav peb cov lus teb raws li 300 J/˚C, lossis 300 Joules ib qib Celsius.
Yog tias koj ntsuas lub zog cua sov hauv calories thiab ntsuas kub hauv Kelvin, koj cov lus teb kawg yog 300 Cal/K
Kauj Ruam 4. Paub tias qhov sib npaug no ua haujlwm rau cov khoom uas txias ib yam nkaus
Thaum ib yam khoom ua ob degrees txias dua, nws poob zoo ib yam ntawm cov cua sov raws li nws yuav ua kom sov 2 degrees. Yog li, yog koj nug, "Lub peev xwm cua sov ntawm ib yam khoom twg yog tias nws poob 50 Joules lub zog thiab nws qhov kub tau poob 5 degrees Celsius," koj tseem tuaj yeem siv qhov sib npaug no:
- Muaj peev xwm ua kom sov: 50 J/ 5˚C
- Cov cua sov muaj peev xwm = 10 J/˚C
Txoj Kev 2 ntawm 2: Siv Qhov Tshav Kub Kub Tshwj Xeeb
Kauj Ruam 1. Paub tias cov cua sov tshwj xeeb hais txog lub zog xav tau txhawm rau nce qhov kub ntawm ib gram ntawm cov khoom los ntawm ib qib
Thaum koj saib lub peev xwm cua sov ntawm ib chav ntawm cov teeb meem (1 gram, 1 ounce, 1 kilogram, thiab lwm yam), koj tau saib rau qhov tshwj xeeb cua sov ntawm cov khoom no. Cov cua sov tshwj xeeb qhia txog lub zog xav tau kom nce qhov kub ntawm txhua chav ntawm ib qho khoom los ntawm ib qib. Piv txwv li, txhawm rau nce qhov kub ntawm 1 gram dej los ntawm 1 degree Celsius xav tau 0.417 Joule ntawm lub zog. Yog li, qhov dej sov tshwj xeeb yog 0.417 J/˚C ib gram.
Cov cua sov tshwj xeeb ntawm cov khoom siv yog qhov tas li. Qhov no txhais tau tias txhua yam dej ntshiab muaj qhov kub tshwj xeeb, uas yog 0.417 J/˚C
Kauj Ruam 2. Siv cov mis muaj peev xwm ua kom sov kom pom cov cua sov tshwj xeeb ntawm cov khoom siv
Nrhiav cov cua sov tshwj xeeb yog yooj yim, uas yog, faib cov lus teb kawg los ntawm qhov hnyav ntawm qhov khoom. Cov txiaj ntsig tau qhia ntau npaum li cas lub zog xav tau rau txhua qhov khoom, xws li tus naj npawb ntawm joules xav tau los hloov qhov kub ntawm tsuas yog ib gram ntawm cov dej khov.
- Piv txwv li: "Kuv muaj 100 grams dej khov. Ua kom cov dej khov sov li 2 degrees Celsius nws yuav siv 406 Joules - qhov sov tshwj xeeb ntawm cov dej khov yog dab tsi?"
- Peev Xwm Kub rau 100 g Dej khov = 406 J/ 2˚C
- Peev Xwm Kub rau 100 g Dej khov = 203 J/˚C
- Lub peev xwm cua sov rau 1 g Dej khov = 2.03 J/˚C ib gram
- Yog tias koj tsis meej pem, xav txog nws li no - kom nce qhov kub los ntawm ib qib rau txhua gram ntawm cov dej khov nws yuav siv sij hawm 2.03 Joules. Yog li, yog tias peb muaj 100 grams dej khov, peb xav tau 100 npaug ntau dua Joules kom sov nws tag nrho.
Kauj Ruam 3. Siv cov cua sov tshwj xeeb txhawm rau nrhiav lub zog xav tau txhawm rau nce qhov kub ntawm cov khoom siv mus rau qhov kub
Cov cua sov tshwj xeeb ntawm cov teeb meem qhia txog lub zog xav tau txhawm rau nce qhov kub ntawm ib chav ntawm cov teeb meem (feem ntau yog 1 gram) los ntawm ib qib. Txhawm rau nrhiav cov cua sov xav tau kom nce qhov kub ntawm ib yam khoom mus rau qhov kub, peb tsuas yog muab txhua qhov seem. Yuav Tsum Muaj Zog = Pawg X Tshwj Xeeb Kub X Hloov Kub. Cov lus teb yog ib txwm nyob hauv chav ntawm lub zog, xws li Joules.
- Piv txwv: "Yog tias cov cua sov tshwj xeeb ntawm txhuas yog 0.902 Joules ib gram, pes tsawg Joules xav tau kom nce qhov kub ntawm 5 grams txhuas los ntawm 2 degrees Celsius?
- Lub zog xav tau = 5 g x 0.902 J/g˚C x 2˚C
- Lub zog xav tau = 9.02 J
Kauj Ruam 4. Paub cov cua sov tshwj xeeb ntawm cov khoom siv sib xws
Txhawm rau pab xyaum, kawm ntau yam tshwj xeeb cov cua sov, uas koj tuaj yeem pom ntawm kev xeem lossis tshwm sim hauv lub neej tiag tiag. Koj kawm tau dab tsi los ntawm qhov no? Piv txwv li, nco ntsoov tias cov cua sov tshwj xeeb ntawm cov hlau yog qis dua li ntawm cov ntoo - qhov no yog vim li cas cov hlau diav ua kom sov sai dua ntoo yog tias nyob hauv lub khob kub qhob noom xim kasfes. Cov cua sov tshwj xeeb qis dua txhais tau tias cov khoom ua kom sov dua.
- Dej: 4,179 J/g˚C
- Huab cua: 1.01 J/g˚C
- Ntoo: 1.76 J/g˚C
- Txhuas: 0.902 J/g˚C
- Kub: 0.129 J/g˚C
- Hlau: 0.450 J/g˚C
Lub tswv yim
- International (SI) chav tsev muaj peev xwm ua kom sov yog Joules per Kelvin, tsis yog Joules
- Kev hloov pauv ntawm qhov kub thiab txias yog sawv cev los ntawm chav ntsuas kub tsis yog ib chav ntsuas kub (hais tias: 30 Delta K hloov chaw tsuas yog 30K)
- Lub zog (cua sov) yuav tsum yog hauv Joules (SI) [Pom Zoo]
