Thermodynamics - matsaloli da mafita
Ka'idar farko ta thermodynamics
1. Dangane da jadawalin PV da ke ƙasa, menene rabon aikin da iskar gas ta yi a cikin tsari na I, da aikin da iskar gas ta yi a cikin tsari na II?
An sani:
Tsarin 1:
Matsi (P) = 20 N/m 2
Ƙarar farko (V1 ) = lita 10 = 10 dm 3 = 10 x 10 -3 m 3
Ƙarar ƙarshe (V2 ) = lita 40 = 40 dm 3 = 40 x 10 -3 m 3
Tsarin 2:
Tsarin (P) = 15 N/m 2
Ƙarar farko (V1 ) = lita 20 = 20 dm 3 = 20 x 10 -3 m 3
Ƙarar ƙarshe (V2 ) = lita 60 = 60 dm 3 = 60 x 10 -3 m 3
Ana so: Rabon aikin da gas ke yi
Magani:
Aikin da gas ke yi a cikin tsari na:
W = P ΔV = P (V2 –V1 ) = (20)(40-10)(10 -3 m3 ) = (20)(30)(10 -3 m3 ) = (600)(10 -3 m3 ) = 0.6 m3
Aikin da iskar gas ke yi a cikin tsari na II:
W = P ΔV = P (V2 –V1 ) = (15)(60-20)(10 -3 m3 ) = (15)(40)(10 -3 m3 ) = (600)(10 -3 m3 ) = 0.6 m3
Rabon aikin da iskar gas ta yi a cikin tsari na I da tsari na II:
0.6 m 3 : 0.6 m 3
1: 1
2.
Dangane da jadawalin da ke ƙasa, menene aikin da iskar helium ke yi a cikin tsarin AB?
An sani:
Matsi (P) = 2 x 10 5 N/m 2 = 2 x 10 5 Pascals
Ƙarar farko (V1 ) = 5 cm 3 = 5 x 10 -6 m 3
Ƙarar ƙarshe (V2 ) = 15 cm 3 = 15 x 10 -6 m 3
Ana nema: Aikin da gas ke yi a cikin tsarin AB
Magani:
W = ∆P ∆V
W = P (V 2 – V 1 )
W = (2 x 10 5 )(15 x 10 -6 – 5 x 10 -6 )
W = (2 x 10 5 )(10 x 10 -6 ) = (2 x 10 5 )(1 x 10 -5 )
W = Joule 2
3.
Dangane da jadawalin da ke ƙasa, menene aikin da aka yi a cikin tsari AB?
An sani:
Matsi na farko (P1 ) = 4 Pa = 4 N/ m2
Matsi na ƙarshe (P2 ) = 6 Pa = 6 N/ m2
Ƙarar farko (V1 ) = 2 m3
Ƙarar ƙarshe (V2 ) = 4 m3
Ana so: aikin da aka yi Ina sarrafa ab
Magani:
Aikin da gas ke yi = yanki a ƙarƙashin lanƙwasa ab
W = yankin alwatika + yankin murabba'i mai kusurwa huɗu
W = ½ (6-4)(4-2) + 4(4-2)
W = ½ (2)(2) + 4(2)
W = 2 + 8
W = Joule 10
4. Dangane da jadawalin da ke ƙasa, menene aikin da aka yi a cikin tsari na ABCA.
Magani:
Aiki (W) = Yankin alwatika ABC
W = ½ (20-10)(6 x 10 5 – 2 x 10 5 )
W = ½ (10)(4 x 10 5 )
W = (5)(4 x 10 5 )
W = 20 x 10 5
W = 2 x 10 Joule 6
5. Injin yana shan Joules 2000 na zafi a babban zafin jiki kuma yana fitar da Joules 1200 na zafi a ƙaramin zafin jiki. Menene ingancin injin?
An sani:
Shigar da zafi (Q H ) = Joules 2000
Fitar da zafi (Q L ) = Joules 1200
Aikin da injin (W) ke yi = 2000 – 1200 = Joules 800
Ana so: inganci (e)
Magani:
e = W / Q H
e = 800/2000
e = 0.4 x 100%
e = 40%
6. Injin yana shan zafi a 960 Kelvin kuma injin yana fitar da zafi a 576 Kelvin. Menene ingancin injin?
An sani:
Zafin jiki mai yawa (T H ) = 960 K
Ƙananan zafin jiki (T L ) = 576 K
Ana so: inganci (e)
Magani:
Ingancin injin Carnot = 0.4 x 100% = 40%
7. Dangane da jadawalin da ke ƙasa, aikin da injin ɗin ke yi shine Joules 6000. Nawa ne zafin da injin ke fitarwa a kowace da'ira?
An sani:
Aiki (W) = Joule 6000
Zafin jiki mai yawa (T H ) = 800 Kelvin
Ƙananan zafin jiki (T L ) = 300 Kelvin
Ana so: zafi da injin ke fitarwa
Mafita :
Inganci mai kyau (wanda aka tsara):
Zafin da injin Carnot ke sha:
W = e Q1
6000 = (0.625) Q1
Q1 = 6000 / 0.625
Q1 = 9600
Zafin da injin Carnot ke fitarwa:
Q2 = Q1 – W
Q2 = 9600 – 6000
Q2 = Joule 3600
8. Ingancin injin Carnot shine kashi 40%. Idan aka sha zafi a zafin digiri 727 na Celsius to menene ƙarancin zafin.
An sani:
Inganci (e) = 40% = 40/100 = 0.4
Zafin jiki mai yawa (T H ) = 727 o C + 273 = 1000 K
Ana so: Ƙananan zafin jiki
Magani:
T L = 600 Kelvin – 273 = 327 o C
9. Dangane da jadawalin da ke ƙasa, idan injin ya sha zafi mai ƙarfin 800 J, menene aikin da injin ɗin ke yi?
An sani:
Zafin jiki mai yawa (T H ) = 600 Kelvin
Ƙananan zafin jiki (T L ) = 250 Kelvin
Shigar da zafi (Q1 ) = Joules 800
Ana nema: Aiki (W)
Magani:
Ingancin injin Carnot:
Injin ya yi aikin:
W = e Q1
W = (7/12)(Joules 800)
W = Joule 466.7
10. Zafin injin Carnot mai girma shine 600 K. Idan injin ya sha 600 J na zafi kuma ƙaramin zafin shine 400 K, menene aikin injin ɗin?
An sani:
Ƙananan zafin jiki (T L ) = 400 K
Zafin jiki mai yawa (T H ) = 600 K
Shigar da zafi (Q1 ) = Joules 600
Ana nema: Injin Carnot (W) ne ya yi aikin
Magani:
Ingancin injin Carnot:
Injin Carnot ne ya yi aikin:
W = e Q1
W = (1/3)(600) = Joule 200
- Menene babban abin da thermodynamics ke mayar da hankali a kai? Amsa: Thermodynamics yana mai da hankali kan nazarin makamashi, sauye-sauyensa, da kuma alaƙarsa da abu, musamman a cikin tsarin da ke daidaita daidaito.
- Ta yaya dokar sifili ta thermodynamics ke da alaƙa da yanayin zafi? Amsa: Dokar sifili ta bayyana cewa idan tsarin biyu kowannensu yana cikin daidaiton zafi tare da tsarin na uku, to suna cikin daidaiton zafi tare da juna. Wannan yana nufin wanzuwar wani abu da ake kira zafin jiki, wanda iri ɗaya ne ga dukkan tsarin a cikin daidaiton zafi.
- Menene dokar farko ta thermodynamics ta bayyana? Amsa: Dokar farko, wadda aka fi sani da dokar kiyaye makamashi, ta bayyana cewa ba za a iya ƙirƙirar ko lalata makamashi ba, sai dai a canza shi daga wani tsari zuwa wani. A cikin tsarin da aka rufe, canjin makamashin ciki yana daidai da zafin da aka ƙara wa tsarin ban da aikin da tsarin ke yi a kewayensa.
- Me yasa ka'idar thermodynamics ta biyu take da mahimmanci don fahimtar alkiblar hanyoyin halitta? Amsa: Doka ta biyu ta bayyana cewa entropy (ko rashin lafiya) na tsarin da aka ware koyaushe yana ƙaruwa ko yana ci gaba da kasancewa akai-akai. Wannan yana nuna cewa makamashi yana warwatsewa ba zato ba tsammani idan ba a hana shi yin hakan ba, yana ba da jagora ga hanyoyin halitta kuma a zahiri yana bayyana dalilin da yasa wasu hanyoyin ke faruwa kwatsam yayin da wasu ba sa faruwa.
- Menene entropy, kuma ta yaya yake da alaƙa da rashin tsari a cikin tsarin? Amsa: Entropy ma'auni ne na adadin kuzari a cikin tsarin da ba shi da damar yin aiki. Haka kuma ana siffanta shi sau da yawa a matsayin ma'aunin rashin lafiyar tsarin ko rashin daidaituwar sa. Gabaɗaya, babban entropy yana daidai da babban rashin daidaituwa ko rashin daidaituwa.
- Ta yaya ka'idar thermodynamics ta uku ta bayyana entropy na cikakken lu'ulu'u a sifili? Amsa: Doka ta uku ta bayyana cewa entropy na cikakken lu'ulu'u daidai yake da sifili a yanayin zafi na sifili (0 Kelvin). Wannan yana nufin cewa a wannan yanayin zafi, tsarin yana da tsari daidai.
- Me yasa zafi ba zai iya kwarara daga jiki mai sanyi zuwa jiki mai zafi shi kaɗai ba? Amsa: Wannan ɗabi'a sakamakon dokar thermodynamics ta biyu ce. Idan zafi ya gudana daga jikin da ya fi sanyi zuwa jikin da ya fi zafi kwatsam, zai haifar da raguwar entropy na tsarin gabaɗaya, wanda hanyoyin halitta ba su fifita shi ba.
- Menene bambanci tsakanin tsarin da aka keɓe, wanda aka rufe, da kuma wanda aka buɗe a cikin thermodynamics? AmsaTsarin da aka ware ba ya musayar makamashi ko kwayoyin halitta da muhallinsa. Tsarin da aka rufe zai iya musayar makamashi amma ba shi da wani muhimmanci da muhallinsa. Tsarin da aka bude zai iya musayar makamashi da kwayoyin halitta da muhallinsa.
- Ta yaya manufar "aiki" a cikin thermodynamics ta bambanta da amfani da kalmar yau da kullun? Amsa: A cikin thermodynamics, "aiki" yana nufin tsarin canja wurin makamashi inda ƙarfin da aka yi amfani da shi ga wani abu ke motsa shi a cikin alkibla daidai da ƙarfin. Misali, lokacin da iskar gas ta faɗaɗa akan piston, yana aiki akan piston. Wannan ma'anar takamaiman ce idan aka kwatanta da amfani da "aiki" na yau da kullun, wanda zai iya nufin kowane aiki ko aiki kawai.
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Menene zagayowar Carnot, kuma me yasa yake da mahimmanci a cikin thermodynamics? Amsa : zagayowar Carnot wani tsari ne na thermodynamic wanda aka tsara wanda ke ba da iyaka mafi girma akan ingancin da kowane injin thermodynamic na gargajiya zai iya cimmawa yayin canza zafi zuwa aiki (ko akasin haka). Yana da mahimmanci saboda yana saita ƙayyadadden inganci bisa ga yanayin zafi na ma'ajiyar zafi wanda injin ke aiki a tsakaninsu.
