1. 1-kg wai i te 100 ° C i konatunatua ki te 1-kg wai i te 10 ° C i roto i tētahi pūnaha motuhake. Ko te wera motuhake o te wai ko 4200 J/kg oC . Tātaihia te pāmahana whakamutunga o te ranunga!
Mōhiotia:
Taumaha o te wai wera (m1 ) = 1 kg
Te pāmahana o te wai wera (T 1 ) = 100 ° C
Taumaha o te wai matao (m2 ) = 1 kg
Te pāmahana o te wai matao (T 2 ) = 10 o C
E hiahiatia ana: Te pāmahana whakamutunga (T)
Rongoā:
Te wera i ngaro = Te wera i whiwhi (pūnaha motuhake)
mc ΔT = mc ΔT
m ΔT = m ΔT
m1 ( T1 – T ) = m2 ( T – T2 )
(1)(100 – T) = (1)(T – 10)
100 – T = T – 10
100 + 10 = T + T
110 = 2T
T = 110 / 2
T = 55
Ko te pāmahana whakamutunga he 55 ° C.
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2. He poraka mata 3 kg te taumaha i te 80o whakatakotoria ki roto i te 10 kg o te wai. Ko te wera motuhake o te mata he 1400 J.kg-1C-1 ā, ko te wera motuhake o te wai he 4200 J.kg-1C-1Ko te pāmahana whakamutunga i roto i te taurite wera ko 20oC. Tātaitia te pāmahana tīmatanga o te wai!
Mōhiotia:
Taumaha ( m1 ) = 3 kg
Ko te wera motuhake o te mata (c 1 ) = 1400 J.kg -1 C -1
Ko te pāmahana o te mata (T 1 ) = 80 ° C
Taumaha o te wai (m2 ) = 10 kg
Ko te wera motuhake o te wai (c 2 ) = 4200 J.kg -1 C -1
Ko te pāmahana o te taurite wera (T) = 20 ° C
E hiahiatia ana: Te pāmahana tīmatanga o te wai (T 2 )
Rongoā:
Wera i ngaro = Wera i whiwhi
Q mata = Q wai
m 1 c 1 ΔT = m 2 c 2 ΔT
(3)(1400)(80-20) = (10)(4200)(20-T)
(4200)(60) = (42,000)(20-T)
252,000 = 840,000 – 42,000 T
42,000 T = 840,000 – 252,000
42,000 T = 588,000
T = 588,000 / 42,000
T = 14
Ko te pāmahana tīmatanga o te wai he 14 ° C.
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3. He poraka parahi i 100oC i roto i te 128 karamu o te wai 30 oC. Ko te wera motuhake o te wai ko 1 cal.g-1oC-1 ā, ko te wera motuhake o te parahi he 0.1 cal.g-1oC-1. Mena ko te pāmahana o te taurite wera he 36 oC, whakatauria te taumaha o te parahi!
Mōhiotia:
Ko te pāmahana o te parahi (T 1 ) = 100 ° C
Ko te wera motuhake o te parahi (c 1 ) = 0.1 c al.g -1o C -1
Taumaha o te wai (m2 ) = 128 karamu
Te pāmahana o te wai (T 2 ) = 30 ° C
Ko te wera motuhake o te wai (c 2 ) = 1 c al.g -1o C -1
Ko te pāmahana o te taurite wera (T) = 36 ° C
E hiahiatia ana: Taumaha o te parahi ( m1 )
Rongoā:
Wera i ngaro = Wera i whiwhi
Q parahi = Q wai
m 1 c 1 ΔT = m 2 c 2 ΔT
(m 1 )(0.1)(100-36) = (128)(1)(36-30)
(m 1 )(0.1)(64) = (128)(1)(6)
(m 1 )(6.4) = 768
m1 = 768 / 6.4
m1 = 120
Ko te taumaha o te parahi he 120 karamu.
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4. He poraka hukapapa M-kg i 0oC ringihia ki roto i te 340 karamu o te wai 20oC i roto i te oko. Mena te te wera o te hanumitanga mo te wai = 80 karori karamu-1, ko te wera motuhake o te wai 1 karori karamu-1 oC-1. Ka rewa katoa te hukapapa, ā, ka pāmahana hoki taurite wera is 5oC, whakatauria te papatipu o te huka!
Mōhiotia:
Taumaha o te wai (m) = 340 karamu
Ko te pāmahana o te hukapapa (T hukapapa ) = 0 ° C
Te pāmahana o te wai (T wai ) = 20 ° C
Ko te pāmahana o te taurite wera (T) = 5 o C
Ko te wera o te hanumitanga mō te wai ( L ) = 80 karori karori -1
Ko te wera motuhake o te wai (c wai ) = 1 karori karamu -1 o C -1
E hiahiatia ana: Taumaha o te hukapapa (M)
Rongoā:
Wera i ngaro = Wera i whiwhi
Q wai = Q hukapapa
m c ( ΔT) = m e L es + m c ( Δ T)
(340)(1)(20-5) = M (80) + M (1)(5-0)
(340)(15) = 80M + 5M
5100 = 85M
M = 5100/85
M = 60 karamu
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- Te huri i ngā tauine pāmahana
- Whānuitanga rārangi
- Te whakawhānui ake i te rohe
- Whakawhanuitanga rōrahi
- Heat
- Te ōrite ā-pūkaha o te wera
- Te wera motuhake me te kaha wera
- Te wera huna, te wera o te hanumi, te wera o te mimiti
- Te tiaki pūngao mō te whakawhiti wera
