ʻAtikala e pili ana i ka Hoʻopili ʻana o ke Kānāwai Mua o Thermodynamics i kekahi mau kaʻina hana Thermodynamic
Ua kūkākūkā mua mākou Ke Kānāwai Mua o ka Thermodynamics a kālailai hana i hoʻokō ʻia e ka ʻōnaehana. I kēia manawa, e nānā mākou i kekahi mau noi o ke Kānāwai Mua o Thermodynamics i ʻehā mau kaʻina hana thermodynamic. ʻO nā kaʻina hana thermodynamic ʻehā i nīnau ʻia he isothermal, isochoric, isobaric, a me adiabatic. Loaʻa kēia mau huaʻōlelo mai ka Helene mai.
Kaʻina Hana Isothermal (mahana mau)
ʻO ka mea mua, e nānā hou kākou i ka hoʻopili ʻana o ke kānāwai mua o ka thermodynamics i kahi kaʻina hana isothermal. I loko o kahi kaʻina hana isothermal, mālama ʻia ka mahana o ka ʻōnaehana. ʻO ka ʻōnaehana a mākou e kālailai nei ma ke kumumanaʻo he kinoea kūpono. Pili pono ka mahana o kahi kinoea kūpono i ka ikehu kūloko o ke kinoea kūpono (U = 3/2 nRT). ʻOiai ʻo T e mau ana, e mau ana nō hoʻi ʻo U. No laila, i ka wā e hoʻopili ʻia ai i kahi kaʻina hana isothermal, lilo ka hoohalike no ke kānāwai mua o ka thermodynamics:
Mai kēia mau hopena hiki ke hoʻoholo ʻia ma ke kaʻina hana isothermal (mahana mau), ʻo ka wela (Q) i hoʻohui ʻia i ka ʻōnaehana e hoʻohana ʻia e ka ʻōnaehana e hana i ka hana (W).
Ua hōʻike ʻia nā loli o ke kaomi a me ka leo o ka ʻōnaehana i loko o kahi kaʻina hana isothermal ma ka pakuhi ma lalo nei:
I ka wā mua, ʻo ka nui o ka ʻōnaehana = V1 (ka nui liʻiliʻi) a me ke kaomi ʻōnaehana = P1 (kaomi kiʻekiʻe). No ka mālama ʻana i ka mahana o ka ʻōnaehana, ma hope o ka hoʻohui ʻia ʻana o ka wela i ka ʻōnaehana, hoʻonui ka ʻōnaehana a hana i ka hana ma ke kaiapuni. Ma hope o ka hana ʻana o ka ʻōnaehana ma ke kaiapuni, loli ka nui o ka ʻōnaehana i V2 (e piʻi ka nui o ka ʻōnaehana) a loli ke kaomi o ka ʻōnaehana i P2 (e emi ana ke kaomi o ka ʻōnaehana). Piʻo ke kiʻikuhi no ka mea ʻaʻole loli mau ke kaomi o ka ʻōnaehana i ka wā o ke kaʻina hana. ʻO ka nui o ka hana i hana ʻia e ka ʻōnaehana = ka wahi i hoʻoluʻu ʻia.
Kaʻina hana Adiabatic
I loko o kahi kaʻina hana adiabatic, ʻaʻohe wela i hoʻohui ʻia a i ʻole e haʻalele i ka ʻōnaehana (Q = 0). Hiki ke hana ʻia nā kaʻina hana adiabatic i nā ʻōnaehana pani ʻia a hoʻokaʻawale maikaʻi ʻia. No kahi ʻōnaehana pani ʻia a hoʻokaʻawale maikaʻi ʻia, ʻaʻohe wela e kahe ana i loko a i ʻole e haʻalele i ka ʻōnaehana i ka makemake. Hiki nō hoʻi ke hana ʻia nā kaʻina hana adiabatic i nā ʻōnaehana pani ʻia a hoʻokaʻawale ʻole ʻia.
I kēia hihia, pono e hoʻokō koke ʻia ke kaʻina hana i ʻole e loaʻa ka manawa e kahe ai ka wela i loko a i waho paha o ka ʻōnaehana. Ke hoʻopili ʻia i kahi kaʻina hana adiabatic, loli ke kānāwai mua o ka hoʻohālikelike Thermodynamics i kēia ʻano:
Inā hoʻopaʻa koke ʻia ka ʻōnaehana (hana ʻia ka hana ma ka ʻōnaehana), a laila maikaʻi ʻole ka hana. No ka mea maikaʻi ʻole ʻo W, a laila maikaʻi ʻo U (piʻi ka ikehu i loko o ka ʻōnaehana). I ka ʻaoʻao ʻē aʻe, inā hoʻonui a ākea koke paha ka ʻōnaehana (hana ka ʻōnaehana), a laila maikaʻi ʻo W. No ka mea maikaʻi ʻo W, a laila maikaʻi ʻole ʻo U (emi ka ikehu i loko o ka ʻōnaehana). Pili pono ka ikehu i loko o ka ʻōnaehana (kinoea kūpono) i ka mahana (U = 3/2 nRT), no laila inā piʻi ka ikehu i loko o ka ʻōnaehana a laila piʻi pū ka mahana o ka ʻōnaehana. I ka ʻaoʻao ʻē aʻe, inā emi ka ikehu i loko o ka ʻōnaehana a laila emi ka mahana o ka ʻōnaehana.
Ua hōʻike ʻia nā loli i ke kaomi a me ka leo o ka ʻōnaehana i loko o kahi kaʻina hana adiabatic ma ka pakuhi ma lalo nei:
Inā hoʻopaʻa koke ʻia ka ʻōnaehana (hana ʻia ka hana ma ka ʻōnaehana), a laila maikaʻi ʻole ka hana. No ka mea maikaʻi ʻole ʻo W, a laila maikaʻi ʻo U (piʻi ka ikehu i loko o ka ʻōnaehana). I ka ʻaoʻao ʻē aʻe, inā hoʻonui a ākea koke paha ka ʻōnaehana (hana ka ʻōnaehana), a laila maikaʻi ʻo W. No ka mea maikaʻi ʻo W, a laila maikaʻi ʻole ʻo U (emi ka ikehu i loko o ka ʻōnaehana). Pili pono ka ikehu i loko o ka ʻōnaehana (kinoea kūpono) i ka mahana (U = 3/2 nRT), no laila inā piʻi ka ikehu i loko o ka ʻōnaehana a laila piʻi pū ka mahana o ka ʻōnaehana. I ka ʻaoʻao ʻē aʻe, inā emi ka ikehu i loko o ka ʻōnaehana a laila emi ka mahana o ka ʻōnaehana.
Ua hōʻike ʻia nā loli i ke kaomi a me ka leo o ka ʻōnaehana i loko o kahi kaʻina hana adiabatic ma ka pakuhi ma lalo nei:
ʻOi aku ka ʻoi o ke kiʻikuhi adiabatic ma kēia kiʻikuhi (nā kiʻikuhi 1-2) ma mua o ke kiʻikuhi isothermal (nā kiʻikuhi 1-3). Hōʻike kēia ʻokoʻa i ke ʻoi ʻana no ka piʻi like ʻana o ka leo, emi nui ka emi ʻana o ke kaomi o ka ʻōnaehana i ke kaʻina hana adiabatic i hoʻohālikelike ʻia me ke kaʻina hana isothermal. emi nui ka emi ʻana o ke kaomi o ka ʻōnaehana i ke kaʻina hana adiabatic no ka mea i ka wā e hoʻonui ʻia ai ka adiabatic, emi pū ka mahana o ka ʻōnaehana. Pili pono ka mahana i ke kaomi, no laila, inā emi ka mahana o ka ʻōnaehana, emi pū ke kaomi o ka ʻōnaehana. I ka ʻaoʻao ʻē aʻe, i loko o kahi kaʻina hana isothermal, mau ka mahana o ka ʻōnaehana. No laila, i loko o kahi kaʻina hana isothermal, ʻaʻole pili ka mahana i ka emi ʻana o ke kaomi.
ʻO kekahi laʻana o ke kaʻina hana e hoʻokokoke ana i ka hoʻopili adiabatic e hana ʻia i loko o nā ʻenekini kuni kūloko, e like me nā ʻenekini diesel a me ka gasoline. I loko o kahi ʻenekini diesel, huki ʻia ka ea i loko o kahi cylinder a hoʻopili koke ʻia me ka hoʻohana ʻana i ka piston (hana ʻia ka hana ma ka ea). Hōʻike ʻia ke kaʻina hana hoʻopili adiabatic (hōʻemi i ka nui o ka ʻōnaehana) e ka curve 2-1. No ka mea ua hoʻopili koke ʻia ka ea ma ke ʻano adiabatically, piʻi koke ka mahana o ka ea. I ka manawa like, pīpī ʻia ka diesel i loko o ka cylinder ma o kahi injector, a hoʻā koke ʻia ka hui ʻana (hana ʻia ka puhi ʻana). I loko o kahi ʻenekini gasoline, huki ʻia ka hui ʻana o ka ea-gasoline i loko o ka cylinder a hoʻopili koke ʻia me ka hoʻohana ʻana i ka piston. No ka mea he adiabatic wikiwiki ka hoʻopili ʻana, piʻi koke kona mahana. I ka manawa like, hana ka spark plug i kahi huna ahi, e hana ana i ka puhi ʻana.
Ke kaʻina hana Isochoric (ka nui mau)
I loko o ke kaʻina hana isochoric, ua mau ka nui o ka ʻōnaehana. No ka mea, ua mau ka nui o ka ʻōnaehana, ʻaʻole hiki i ka ʻōnaehana ke hana i ka hana ma nā mea e puni ana. Pēlā nō, ʻaʻole hiki i nā mea e puni ana ke hana i ka hana ma ka ʻōnaehana. Ke hoʻopili ʻia i kahi kaʻina hana isochoric, lilo ka hoohalike o ke Kanawai Mua o Thermodynamics:
Mai kēia mau hopena, hiki iā mākou ke hoʻoholo i loko o kahi kaʻina hana isochoric (ka nui mau), hoʻohana ʻia ka wela (Q) i hoʻohui ʻia i ka ʻōnaehana e hoʻonui i ka ikehu kūloko o ka ʻōnaehana.
Ua hōʻike ʻia nā loli o ke kaomi a me ka leo o ka ʻōnaehana i loko o kahi kaʻina hana isochoric ma ka pakuhi ma lalo nei:
Kaomi ʻōnaehana mua = p1 (kaomi haʻahaʻa). ʻO ka hoʻohui ʻana o ka wela i ka ʻōnaehana e hoʻonui ai i ka ikehu i loko o ka ʻōnaehana. Ma muli o ka piʻi ʻana o ka ikehu i loko o ka ʻōnaehana, piʻi ka mahana o ka ʻōnaehana (kinoea kūpono) (U = 3/2 nRT). Pili pono ka mahana i ke kaomi. No laila, inā piʻi ka mahana o ka ʻōnaehana, piʻi ke kaomi o ka ʻōnaehana (p2). ʻOiai ʻo ka nui o ka ʻōnaehana he paʻa, ʻaʻohe hana i hana ʻia (ʻaʻohe wahi i hoʻomalulu ʻia).
E like me ka mea i ʻōlelo ʻia ma mua, i loko o ke kaʻina hana isochoric, ʻaʻole hiki i ka ʻōnaehana ke hana i ka hana ma ke kaiapuni. Pēlā nō, ʻaʻole hiki i ke kaiapuni ke hana i ka hana ma ka ʻōnaehana. ʻO kēia no ka mea i loko o ke kaʻina hana isochoric, e mau ana ka leo o ka ʻōnaehana, ʻo ia hoʻi, ʻaʻole ia e loli. ʻAʻole pili kekahi mau ʻano hana i nā loli i ka leo. No laila, ʻoiai inā e mau ana ka leo o ka ʻōnaehana, hiki nō ke hana ʻia ka hana ma ka ʻōnaehana. No ka laʻana, aia kahi peʻahi a me kahi pākahiko i loko o kahi pahu pani. Hiki i ka peʻahi ke hoʻohuli me ka hoʻohana ʻana i ka ikehu i hāʻawi ʻia e ka pākahiko. I kēia hihia, ua manaʻo ʻia ka peʻahi, ka pākahiko, a me ka ea i loko o ka pahu he ʻōnaehana.
Ke hoʻohuli ka peʻahi, hana ia ma ka ea i loko o ka pahu. I ka manawa like, hoʻololi ʻia ka ikehu kinetic o ka peʻahi i ikehu i ka lewa. Hoʻemi maoli ʻia ka ikehu uila i loko o ka pila no ka mea ua hoʻololi ʻia i ikehu i ka lewa. Hōʻike kēia laʻana i loko o kahi kaʻina hana isochoric (ka nui mau), hiki nō ke hana ʻia ka hana ma ka ʻōnaehana (hana ʻaʻole pili i ka loli o ka nui).
Kaʻina hana Isobaric (kaomi mau)
I loko o ke kaʻina hana isobaric, ua mau ke kaomi o ka ʻōnaehana. No ka mea, ʻo ke kaomi mau ke kaomi, ʻaʻole loa e like me ka zero nā loli o ka ikehu kūloko (delta U), ka wela (Q), a me ka hana (W) i loko o ke kaʻina hana isobaric. No laila, ua mau ke kānāwai mua o ka thermodynamics:
ΔU = Q − W
Ua hōʻike ʻia nā loli o ke kaomi kinoea a me ka nui i ke kaʻina hana isobaric ma ka pakuhi ma lalo nei:
I ka wā mua, ʻo ka nui o ka ʻōnaehana = V1 (ka nui liʻiliʻi). No ka mea, ua mau ke kaomi, ma hope o ka hoʻohui ʻia ʻana o ka wela i ka ʻōnaehana, hoʻonui ka ʻōnaehana a hana i ka hana ma ke kaiapuni. Ma hope o ka hana ʻana ma ke kaiapuni, loli ka nui o ka ʻōnaehana i V2 (piʻi ka nui o ka ʻōnaehana). ʻO ka nui o ka hana (W) i hana ʻia e ka ʻōnaehana = ka wahi i hoʻoluʻu ʻia.
Laʻana nīnau 1:
Hōʻike nā piʻo 1-2 ma nā kiʻikuhi ʻelua ma lalo nei i ka hoʻonui ʻia ʻana o ke kinoea (ka piʻi ʻana o ka nui o ke kinoea) e hana ʻia ana ma ke ʻano adiabatically a me ka isothermally. Ma ke kaʻina hana hea ka hana i hana ʻia e ke kinoea i emi iho?
ʻOi aku ka liʻiliʻi o ka hana i hana ʻia e ke kinoea ma ke kaʻina hana adiabatic ma mua o ka hana i hana ʻia e ke kinoea ma ke kaʻina hana isothermal. ʻO ka wahi i hoʻoluʻu ʻia = ka hana i hana ʻia e ke kinoea i ka wā o ke kaʻina hana hoʻonui (ka piʻi ʻana o ka nui o ke kinoea). ʻOi aku ka liʻiliʻi o ka wahi i hoʻoluʻu ʻia ma ke kaʻina hana adiabatic ma mua o ka wahi i hoʻoluʻu ʻia ma ke kaʻina hana isothermal.
Laʻana nīnau 2:
Ua hōʻike ʻia kekahi mau kaʻina hana thermodynamic ma ke kiʻikuhi ma lalo nei. Nā piʻo a-b a me d-c = nā kaʻina hana isochoric (ka nui mau). Nā piʻo b-c a me a-d = nā kaʻina hana isobaric (kaomi mau). Ma ke kaʻina hana a-b, ua hoʻohui ʻia he 600 Joules o ka wela (Q) i ka ʻōnaehana. Ma ke kaʻina hana b-c, ua hoʻohui ʻia he 800 Joules o ka wela (Q) i ka ʻōnaehana. E hoʻoholo:
a) Nā loli i ka ikehu kūloko i nā kaʻina hana a-b
b) Nā loli i ka ikehu kūloko i ke kaʻina hana a-b-c
c) Ka wela holoʻokoʻa i hoʻohui ʻia i ke kaʻina hana a-d-c
P1 = 2x105 Pa = 2 x 105 M / m2
P2 = 4x105 Pa = 4 x 105 M / m2
V1 = 2 lita = 2 dm3 = 2x103 m3
V2 = 4 lita = 2 dm3 = 4x103 m3
Pahana
a) Nā loli i ka ikehu kūloko i nā kaʻina hana a-b
Ma ke kaʻina hana a-b, ua hoʻohui ʻia he 600 J o ka wela i ka ʻōnaehana. ʻO ke kaʻina hana a-b he kaʻina hana isochoric (ka nui mau). Ma ke kaʻina hana isochoric, ʻo ka hoʻohui ʻana o ka wela i ka ʻōnaehana e hoʻonui wale i ka ikehu kūloko o ka ʻōnaehana. No laila, ʻo ka loli o ka ikehu kūloko o ka ʻōnaehana ma hope o ka loaʻa ʻana o ka hāʻawi wela penei:
ʻΔU = Q
ʻΔU = 600 J
b) Nā loli i ka ikehu kūloko i ke kaʻina hana a-b-c
Kaʻina hana a-b = kaʻina hana isochoric (ka nui mau). Ma ke kaʻina hana a-b, ua hoʻohui ʻia he 600 J o ka wela.
i ka ʻōnaehana. No ka mea, paʻa ka leo, ʻaʻohe hana i hana ʻia e ka ʻōnaehana.
Kaʻina hana b-c = kaʻina hana isobaric (kaomi mau). I ke kaʻina hana b-c, ua hoʻohui ʻia he 800 Joules o ka wela (Q) i ka ʻōnaehana. I loko o kahi kaʻina hana isobaric, hiki i ka ʻōnaehana ke hana i ka hana. ʻO ka nui o ka hana i hana ʻia e ka ʻōnaehana ma ke kaʻina hana b-c (kaʻina hana isobaric):
W = P (V2 - V1) -‐‐‐ kaomi mau
W = P2 (V2 - V1)
W = 4 x 105 M / m2 (4x103 m3 ‐ 2 x 103 m3)
W = 4 x 105 M / m2 (2x103 m3)
W = 8 x 102 Joule
W = 800 Joule
ʻO ka wela holoʻokoʻa i hoʻohui ʻia i ka ʻōnaehana ma ke kaʻina hana a-b-c penei:
Huina Q = Q ab + Q bc
Huina Q = 600 J + 800 J
Q huina = 1400 Joule
ʻO ka huina o ka hana i hana ʻia e ka ʻōnaehana ma ke kaʻina hana a-b-c penei:
Huina W = W ab + W bc
Huina W = 0 + W bc
Huina W = 0 + 800 Joule
W huina = 800 Joule
ʻO ka loli o ka ikehu i loko o ka ʻōnaehana ma ke kaʻina hana a-b-c penei:
ΔU = Q − W
ΔU = 1400 J − 800 J
ʻΔU = 600 J
Ka loli ʻana o ka ikehu kūloko i ke kaʻina hana a-b-c = 600 J
c) Ka wela holoʻokoʻa i hoʻohui ʻia i ke kaʻina hana a-d-c
Hiki ke loaʻa ka wela holoʻokoʻa i hoʻohui ʻia i ka ʻōnaehana ma o ka hoohalike ma lalo nei:
ΔU = Q − W
Q = ΔU + W
ʻO ka wela holoʻokoʻa i hoʻohui ʻia i ke kaʻina hana a-d-c = ka loli o ka ikehu kūloko i loko o ke kaʻina hana a-d-c + ka hana holoʻokoʻa i hana ʻia ma ke kaʻina hana a-d-c.
Pili ka wela a me ka hana i ka hoʻoili ʻana o ka ikehu ma waena o ka ʻōnaehana a me ke kaiapuni, ʻoiai nā loli i loko ikehu kūloko he hopena ia o ka hoʻoili ʻana o ka ikehu ma waena o ka ʻōnaehana a me ke kaiapuni. No laila, nā loli ikehu kūloko ʻaʻole hilinaʻi i ke kaʻina hana hoʻoili ikehu. I ka ʻaoʻao ʻē aʻe, hilinaʻi nui ka wela a me ka hana i ke kaʻina hana. I loko o kahi kaʻina hana isochoric (ka nui o ka ʻōnaehana mau), ʻo ka hoʻoili ikehu wale nō ma ke ʻano o ka wela, akā ʻaʻole ka hana. I loko o kahi kaʻina hana isobaric (kaomi mau), pili ka hoʻoili ikehu i ka wela a me ka hana. ʻOiai kūʻokoʻa o ke kaʻina hana, pili ka loli o ka ikehu kūloko i nā kūlana mua a me ka hope o ka ʻōnaehana. Inā like nā kūlana mua a me ka hope, like mau ka loli o ka ikehu kūloko, ʻoiai inā ʻokoʻa nā kaʻina hana i komo.
ʻO ke kūlana mua a me ke kūlana hope loa no ke kaʻina hana a-b-c ma ka pakuhi ma luna = ke kūlana mua a me ke kūlana hope loa o ke kaʻina hana a-d-c. No laila, ʻo ka loli o ka ikehu kūloko i ke kaʻina hana a-d-c = 600 J.
Huina hana (W) i hana ʻia ma ke kaʻina hana a-d-c = W ma ke kaʻina hana a-d + W ma ke kaʻina hana d-c.
He kaʻina hana isobaric (kaomi mau) ke kaʻina hana a-d, ʻoiai he kaʻina hana isochoric (ka nui mau) ke kaʻina hana d-c. No ka mea, he mau ka nui, ʻaʻohe hana i hana ʻia ma ke kaʻina hana d-c. ʻO ka mea mua, helu mākou i ka hana i hana ʻia ma ke kaʻina hana a-d.
W ad = P (V2 - V1)
W ad = P1 (V2 - V1)
W ad = 2 x 105 M / m2 (4x103 m3 ‐ 2 x 103 m3)
W ad = 2 x 105 M / m2 (2x103 m3)
W ad = 4 x 102 Joule
W ad = 400 Joule
Huina W = W ma ke kaʻina hana a-d + W ma ke kaʻina hana d-c
W huina = 400 Joules + 0
W huina = 400 Joule
No laila, ʻo ka nui o ka wela i hoʻohui ʻia i ke kaʻina hana a-d-c:
Q = ΔU + W
Q = 600 J + 400 J
Q = 1000 J
Laʻana nīnau 3:
Hoʻololi ʻia ka 1 lita o ka wai i 1671 lita o ka mahu ke hoʻolapalapa ʻia ma ke kaomi o 1 atm. E hoʻoholo i ka loli o ka ikehu kūloko a me ka nui o ka hana i hana ʻia e ka wai ke mahu… (Ka wela o ka mahu ʻana o ka wai = LV = 22,6x105 (J/Kg)
Pahana
Ka nui o ka wai = 1000 kg/m3
LV = 22,6x105 J/Kg
P = 1 atm = 1,013 x 105 Pa = 1,013 x 105 M / m2
V1 = 1 lita = 1 dm3 = 1x103 m3 (Ka nui o ka wai)
V2 = 1671 lita = 1671 dm3 = 1671x103 m3 (Ka nui o ka mahu)
a) Nā loli i ka ikehu kūloko
Ka loli o ka ikehu kūloko = Ka wela i hoʻohui ʻia i ka wai - Hana i hana ʻia e ka wai ke mahu. ʻO ka mea mua, e helu kākou i ka wela (Q) i hoʻohui ʻia i ka wai...
Q = mL V
Ka nuipa (m) o ka wai?
Ka nui o ka wai = ka nui o ka wai / ka nui o ka wai
Nui o ka wai (m) = (ka nui o ka wai) (ka nui o ka wai)
Ka nui o ka wai (m) = (1000 kg/m3)(1 x 103 m3)
Ka nui o ka wai (m) = (1000 kg/m3)(0,001 mika3)
Ka nui o ka wai (m) = 1 Kg
Q = (1 kg)(22,6 x 105 (J/kg)
Q = 22,6 x 105 J
E helu i ka hana (W) i hana ʻia e ka wai ke mahu. Hana ʻia ka paila ʻana o ka wai ma ke kaomi mau (kaʻina hana isobaric).
W = p (V2 - V1)
W = 1,013 x 105 M / m2 (1671x103 m3 - 1 x 103 m3)
W = 1,013 x 105 M / m2 (1670x103 m3)
W = 1691,71 x 102 Joule
W = 1,7 x 105 Joule
Nā loli ikehu i ka wai:
ΔU = Q − W
ΔU = 22,6 x 105 J − 1, 7 x 105 J
ΔU = 20,9 x 105 J
ΔU = 21 x 105 J
21 m 105 Hoʻohana ʻia ka wela i hoʻohui ʻia i ka wai e hoʻonui i kona ikehu kūloko (e lanakila ana i nā mana hoʻowalewale ma waena o nā molekala e mālama ana i ka wai). I nā huaʻōlelo ʻē aʻe, 21 x 105 Hoʻohana ʻia ʻo J e hoʻololi i ka wai i mahu. Ke lilo ka wai i mahu, 1,7 x 105 Hoʻohana ʻia ke koena J e hana i ka hana.
Laʻana nīnau 4:
Hoʻonui koke ʻia ka 1 mole o ke kinoea i loko o kahi cylinder ma ke ʻano adiabatic. ʻO ka mahana mua o ke kinoea he 1000 K. Ma hope o ka hoʻonui ʻana, emi ka mahana o ke kinoea i 500 K. E hoʻoholo i ka hana i hana ʻia e ke kinoea... Kūkākūkā
Hoʻonui ʻia ke kinoea ma ke ʻano adiabatic. I loko o ke kaʻina hana adiabatic, ʻaʻohe wela e komo a haʻalele paha i ka ʻōnaehana. No laila, ʻo ka hana i hana ʻia e ke kinoea = ka loli o ka ikehu kūloko o ke kinoea. Ma ke ʻano makemakika, ua kākau ʻia kēia penei:
ΔU = Q − W a i ʻole W = Q − Δ U → Q = 0
W = 0 − ΔU
W = − ΔU
Hiki iā mākou ke helu i ka loli o ka ikehu kūloko o ke kinoea me ka hoʻohana ʻana i ka hoohalike ikehu kūloko kinoea kūpono:
ΔU = U hopena – U hoʻomaka
ΔU = 3/2 nR (T hope loa - T mua)
ΔU = 3/2 (1 mol)(8,315 J/mol.K)(500 K – 1000 K)
ΔU = 3/2 (1 mol)(8,315 J/mol.K)(-500 K)
ʻΔU = ‐6236,25 J
No laila, ʻo ka nui o ka hana i hana ʻia e ke kinoea penei:
W = − ΔU
W = − ( − 6236 , 25 J )
W = 6236, 25 J
