Rauemi: Te whakamāramatanga o te wera, te kawe wera, te kaha wera
Kua inu tī tio koe, miraka tio, tirikara tio, me ētahi atu? Āe, i te wā e hanga tī tio ana, ka whakaranua e mātou te wai wera, te wai mahana rānei ki roto i te karāhe me ngā poraka tio. He nui ake te pāmahana o te wai wera, o te wai mahana rānei, engari he iti iho te pāmahana o ngā poraka tio. I muri i te pā atu mō tētahi wā, ka huri te ranunga o ngā poraka tio me te tī wera hei tī tio (kua eke te ranunga o ngā poraka tio me te tī mahana ki te pāmahana ōrite). Ka puta te tukanga ōrite ina whakaranua e mātou te wai wera ki te wai matao. I muri i te pā atu, ka huri te wai wera me te wai matao hei wai mahana (kua eke te ranunga o te wai wera me te wai matao ki te pāmahana ōrite). He aha i taea ai e ēnei mea te eke ki te pāmahana ōrite i muri i te pā atu?
Te Whakamāramatanga o te Wera
Ina pā atu ngā mea he rerekē te pāmahana ki a rātou anō, ka puta te whakawhiti wera, e kiia ana he wera, mai i te mea he teitei ake te pāmahana ki te mea he iti iho te pāmahana. Ka mutu tēnei whakawhiti wera ina tae ngā mea e pā ana ki te pāmahana ōrite. Hei tauira, ki te whakaranua e tātou te wai wera ki te wai matao, ka neke te wera mai i te wai wera ki te wai matao. Ina makahia e tātou he rino wera ki roto i te wai matao, ka neke te wera mai i te rino wera ki te wai. Ka mutu te rere o te wera ina tae te rino me te wai ki te pāmahana ōrite. Ina tāpirihia e te tākuta, e te nēhi rānei he inemahana ki tō tinana, ka neke te wera mai i tō tinana ki te inemahana. Ka mutu tēnei whakawhiti wera ina tae tō tinana me te inemahana ki te pāmahana ōrite. Mena he inemahana mercury te inemahana e whakamahia ana, ina tae tō tinana me te inemahana ki te pāmahana ōrite, ka mutu te neke o te mata o te mercury. Ko te tau e whakaaturia ana i runga i te mata o te mercury ko te pāmahana o tō tinana i taua wā.
I te nuinga o te wā, ka neke te wera mai i ngā mea he teitei te pāmahana ki ngā mea he iti te pāmahana. Ko te tikanga o te whakawhiti wera he whakataurite i ngā pāmahana o ngā mea e pā ana tetahi ki tetahi. I te rautau 18, i whakapae ngā tohunga ahupūngao ko te rere o te wera he nekehanga o te wai, he momo wai e kore e kitea (he matū ka taea te rere ngā wai. Kei roto i ngā wai ngā wai me ngā hau. He wai te wai (he wai) nā te mea ka taea te rere. He wai anō hoki te hau nā te mea ka taea te rere). I tapaina tēnei wai ko te caloric . Kāore e whakamahia ana te ariā o te caloric nā te mea i runga i ngā hua o ngā whakamātautau, kāore e taea te whakamātau i te noho o tēnei caloric .
I te rautau 19, i ako tētahi tohunga ahupūngao Ingarihi ko James Prescott Joule (1818-1889) me pēhea te whakamahana i te wai i roto i tētahi ipu mā te whakamahi i tētahi wira whakaoho. I runga i ngā hua o tana whakamātautau, i whakarite a Joule ki te wai i whakamahanatia e te ahi. Ina pā te mura me te ipu kei roto he wai, ka neke te wera mai i te ahi (mahana teitei) ki te wai (mahana iti). Whai muri i te whakarite i te pikinga o te pāmahana wai nā te pā ki te ahi me te pikinga o te pāmahana wai nā te mahi a te kaiwhakaoho, ka whakatau a Joule ko te wera he pūngao e neke ana mai i tētahi mea pāmahana teitei ki tētahi mea pāmahana iti. Ehara te wera i te pūngao (ehara te wera i te momo pūngao motuhake, pērā i te pūngao nekeneke, te pūngao pūmanawa, te pūngao matū, me ētahi atu) . Ko te wera he pūngao e neke ana nā ngā rerekētanga pāmahana . Nō reira, ina rere te wera mai i tētahi mea pāmahana teitei ki tētahi mea pāmahana iti, kei te neke te pūngao mai i te mea pāmahana teitei ki te mea pāmahana iti. Ka mutu te whakawhiti pūngao ina tae ngā mea e pā ana ki te pāmahana kotahi, te taurite wera rānei.
Te kawe wera
He aha i hangaia ai te nuinga o ngā taputapu tunu kai ki te konumohe? Mehemea kei te pupuri tō ringa maui i tētahi wahi whakarewa, ā, kei te pupuri tō ringa matau i te karāhe, kātahi ka pā atu koe ki te whakarewa me te karāhe ki te mura. Ka tere ake te rongo o tō ringa maui, o tō ringa matau rānei i te wera? E pā ana ēnei pātai, me ētahi atu pea ka pātaihia e koe, ki te kawe wera o tētahi mea. Ko te kawe wera o tētahi mea ko tōna kaha ki te... whakawhiti wera mā roto i te mea. Ko ngā mea he nui te kawe wera (k) he kaiārahi wera yang baik (konduktor termal yang baik). Sebaliknya, benda yang memiliki konduktivitas termal kecil merupakan penghantar kalor yang buruk (konduktor termal yang buruk).
Te kaha wera
Ko te kaha wera (C) te nui o te wera e hiahiatia ana hei whakapiki i te pāmahana o tētahi mea katoa mā te kotahi nekehanga. Ko te tātai mō te kaha wera ko:
C = mc
Keterangan : C = kapasitas kalor, m = massa benda, c = wera motuhake mea
