Ki te pā atu ngā mea he rerekē te pāmahana tetahi ki tetahi, he mea noa iho wera ka neke mai i tētahi mea pāmahana teitei ki tētahi mea pāmahana iti. Ka mutu te whakawhiti wera i muri i ngā mea e rua taurite wera. Ka taea te kī ko te whakawhiti wera meinga te huringa te pāmahana ngā mea e pā ana tetahi ki tetahi. I runga i tēnei whakamārama poto, ka whakatauhia ko wera He whanaungatanga tō (Q) ki he mea dan ngā huringa pāmahana (delta T) o te mea. He papatipu (m) tō ia mea, ā, he rerekē anō hoki ngā momo mea.
Whakaheke tātai wera Ka whakamahia e tēnei pepa te whakaaro whaitake. Ka taea e koe te whakamatau i te pono o tēnei whakaaro whaitake i runga i ō wheako o ia rā, ka taea rānei e koe te whakahaere i tētahi whakamātautau.
Te whanaungatanga i waenganui i krere (Q) me phuringa pāmahana (delta T)
E rua ngā ipu kua kī tonu i te wai he rite te taumaha. Ka whakamahanahia te wai mā te whakamahi i ngā mura e rua. He iti ake te mura o tētahi mura, he teitei ake te mura o tētahi mura. Mena ka whakamahanahia ngā mea e rua mō ngā meneti tekau, ko tēhea ipu he wera ake? Mena kua whakamahanahia e koe te wai, ka whakaae koe he wera ake te wai i whakamahanahia mā te whakamahi i te oumu me te mura teitei ake (he teitei ake te pāmahana whakamutunga o te wai, he nui ake rānei te huringa pāmahana).
Ko te mura e tohu ana i te nui o te wera (Q). He iti te wera o te mura iti, he nui te wera o te mura nui. Ina he iti te wera, he iti te huringa pāmahana. Ina he nui te wera, he nui te huringa pāmahana. Ka nui ake te wera, ka nui ake te huringa pāmahana. Ka taea te whakatau ko te nui o te wera (Q) he rite ki te huringa o te pāmahana o te mea.
Te whanaungatanga i waenganui i te wera (Q) me te papatipu o te mea (m)
E rua ngā ipu kua whakakīia ki te wai, he rerekē ngā taumaha, kotahi te ipu kua whakakīia ki te wai nui ake, ko tētahi atu ipu kua whakakīia ki te wai iti iho. Ka whakamahanatia te wai mā te whakamahi i ngā oumu e rua, he rite tonu te mura. Mena ka whakamahanatia ngā mea e rua mō ngā meneti tekau, ko tēhea wai i roto i te ipu he wera ake? Mena kua whakamahanahia e koe te wai, ka whakaae koe he wera ake te wai i roto i te wai iti (he nui ake te pāmahana whakamutunga o te wai, he nui ake rānei te huringa pāmahana). Kia rite ai te huringa pāmahana o te nui o te wai ki te iti o te wai, me whakanui ake te mura e whakamahana ana, he nui ake te wai.
Ko te nui o te wai e tohu ana i te papatipu o te wai (m). Ko te rahi o te mura e tohu ana i te nui o te wera. Ka taea te whakatau ko te nui o te wera (Q) he rite ki te huringa o te pāmahana o te mea. Ka nui ake te wai, ka nui ake te wera e hiahiatia ana hei whakaara ake i te pāmahana o te wai.
Te whanaungatanga i waenganui i te wera (Q) me te momo mea (c)
Ki te whakamahanahia e koe tētahi pae rino me tētahi pae karāhe he rite te rahi i te wā kotahi mā te whakamahi i te mura kotahi, ko tēhea ka tere ake te wera, ko te rino, ko te karāhe rānei? Ae, ka tere ake te wera o te rino. Ka taea te whakatau ko te wera e hiahiatia ana hei whakaara ake i te pāmahana o tētahi mea he rite ki te momo mea.
Ka honoa ngā whakataurite e toru i runga ake nei hei whārite:
Koinei te tātai, te whārite wera rānei.
Ngā Mōhiotanga: Q = wera (Joule), m = papatipu o te mea (kg), c = wera motuhake o te mea (J/kg Co), te rohe T = te huringa o te pāmahana (Co rānei K)
1. E rima kirokaramu o te hukapapa i te pāmahana o te -22oKa whakamahanahia te hukapapa C kia rewa katoa te hukapapa i te pāmahana o te 0oC. Mēnā wera huna hukapapa 333 kJ/kg me te wera motuhake o te hukapapa 2100 J/kg Co, kātahi ka te tau wera ko te mea e hiahiatia ana ko…
A. 1496 kJ
B. 1596 kJ
C. 1696 kJ
D. 1796 kJ
E. 1896 kJ
Kōrero
E mōhiotia ana:
Taumaha o te huka (m) = 5 kg
Te pāmahana tīmatanga (T) = -22oC
Te wera huna o te hukapapa (L) = 333 kJ/kg = 333.000 J/kg
Te wera motuhake o te hukapapa (c) = 2100 J/kg Co
I pātaihia: Te nui o te wera e hiahiatia ana (Q)
Whakautu:
Tukanga 1: whakanuia te pāmahana o te hukapapa mai i te -22oC ki te 0oC
Q = mc ΔT = (5)(2100)(22) = 231.000 Joule
Tukanga 2: rewahia te hukapapa katoa ki roto i te wai
Q = m L = (5)(333.000) = 1.665.000 J
Te wera katoa = 231.000 J + 1.665.000 J = 1.896.000 J = 1.896 kJ
Ko te whakautu tika ko E.
Pūtake pātai:
Ngā Pātai Ahupūngao SBMPTN
