9 Panas Massa Panas spesifik Owah-owahan suhu – Masalah lan Solusi
1. Timah 2 kg dipanasake saka 50oC kanggo 100oC. Ing panas spesifik timbal yaiku 130 J.kg-1 oC-1. Pinten panas diserap dening timah?
Dikenal:
Massa (m) = 2 kg
Panas spesifik (c) = 130 J.kg-1C-1
Owah-owahan suhu (ΔT) = 100oC - 50oC = 50oC
Dikarepake: panas (Q)
Solusi:
Q = mc ΔT
Q = panas, m = massa, c = panas tartamtu, ΔT= owah-owahan suhu
Panas sing diserep dening timbal:
Q = (2 kg)(130 J.kg-1C-1)(50oC)
Q = (100)(1)30)
Q = 13,000 jro
Q = 1.3 x 104 Joule
2. Panas spesifik tembaga yaiku 390 J/kg oC, owah-owahan suhu yaiku 40oC. Yen tembaga nyerep panas 40 Joule, pira massa tembaga kasebut!
Dikenal:
Panas spesifik tembaga (c) = 390 J/kgoC
Owah-owahan suhu (ΔT) = 40oC
Panas (Q) = 40 J
Dikarepake: Massa (m) saka tembaga
Solusi:
Q = mc ΔT
40 J = (m)(390 J/kg oC)(40oC)
40 = (m)(390/kg)(40)
40 = (m)(390/kg)(4)
40 = (m)(1560/kg)
m = 40 / 1560
m = 0.026 kg
m = 26 gram
3. Suhu awal 20 gram banyu yaiku 30oC. Kalor spesifik banyu yaiku 1 kal g-1 oC-1Yen banyu nyerep 300 kalori panas, temtokake suhu pungkasan!
Dikenal:
Massa (m) = 20 gr
Suhu awal (T1) = 30oC
Panas spesifik banyu (c) = 1 kal gr-1 oC-1
panas (Q) = 300 kal
Dikarepake: Suhu pungkasan banyu
Solusi:
Q = mc T
300 kal = (20 gr)(1 kal g-1 oC-1)(T2-30)
300 = (20)(1)(T2-30)
300 = 20 (T2-30)
= 300 20T2 - 600
300 + 600 = 20T2
900 = 20T2
T2 = 900/20
T2 = 45
Owah-owahan suhu yaiku 45oC - 30oC = 15oC.
4. Towah-owahan suhu saka banyu segara is 1oC nalika banyu nyerep 3900 Joule panas. Panas spesifik banyu segara yaiku 3.9 × 103 J/kg°C, pira bobote banyu segara kuwi.
Dikenal:
Owah-owahan suhu (ΔT) = 1oC
panas (Q) = 3900 Joule
Panas spesifik banyu segara (c) = 3.9 x 103 J/kg°C = 3900 J/Kg°C
Dikarepake: Massa (M)
Solusi:
Q = mc ΔT
Q = panas, m = massa, c = panas spesifik, ΔT= owah-owahan suhu
m = Q / c ΔT = 3900 / (3900)(1) = 3900 / 3900 = 1 kg
5. Tembaga 2 kg nyerep panas 39,000 J ing suhu 30°C. Yen panas spesifik tembaga yaiku 390 J/kg °C, pira suhu pungkasan tembaga kasebut…
Dikenal:
Massa (m) = 2 kg
Suhu awal (T1) = 30oC
panas (Q) = 39,000 Joule
Panas tartamtu (c) saka tembaga = 390 J/kg oC
wanted : Suhu pungkasan (T2)
Solusi:
Q = mc T
Q = panas, m = massa, c = panas spesifik, ΔT = owah-owahan suhu
Q = mc ΔT = mc (T2 - T1)
39,000 = (2)(390)(T2 - 30)
100 = (2)(1)(T2 - 30)
100 = (2)(T2 - 30)
50 = T2 - 30
T2 = 50 + 30
T2 = 80oC
6. Banyu 5 kg dipanasake saka suhu 15°C nganti 40°C. Pira panas sing diserap banyu. Panas spesifik banyu yaiku 4.2 × 103 J/Kg°C.
Dikenal:
Massa (m) = 5 kg
Suhu awal (T1) = 15°C
Suhu pungkasan (T2) = 40°C
Panas spesifik banyu (c) = 4.2 × 103 J/kg°C
Dikarepake: panas (Q)
Solusi:
Q = mc T
Q = (5 kg)(4.2 × 103 J/kg°C)(40°C – 15°C)
Q = (5)(4.2 × 103 J)(25)
Q = 525 x 103 J
Q = 525,000 Joule
7. Banyu 2 kg dipanasake saka suhu 24°C nganti 90°C. Pira panas sing diserap banyu. Panas spesifik banyu yaiku 4.2 × 103 J/Kg°C.
Dikenal:
Massa (m) = 2 kg
Suhu awal (T1) = 24°C
Suhu pungkasan (T2) = 90°C
Panas spesifik banyu (c) = 4,200 Joule/kg°C
Dikarepake :: panas (Q)
Solusi:
Q = m c T
Q = (2 kg)(4,200 Joule/kg°C)(90°C – 24°C)
Q = (2 kg)(4,200 Joule/kg°C)(66°C)
Q = (132)(4,200 Joule)
Q = 554,400 Joule
8. Banyu 5 gram dipanasake saka suhu 10°C nganti 40°C. Pira panas sing diserap banyu. Panas spesifik banyu yaiku 1 × 103 cal/gr°C.
Dikenal:
Massa (m) = 5 gram
Suhu awal (T1) = 10oC
Suhu pungkasan (T2) = 40oC
Panas spesifik banyu (c) = 1 cal/ gr°C
wanted : Panas
Solusi:
Q = mc T
Q = (5 gram)(1 kal/gr°C)(40oC - 10oC)
Q = (5)(1 cal)(30)
Q = 150 Kalori
9. Banyu 0.2 kg nyerep 42,000 Joule panas ing 25oC. Panas spesifik banyu yaiku 4200 J/kg oC, pira suhu pungkasan banyu.
Dikenal:
Massa banyu (m) = 0.2 kg
panas (Q) = 42,000 Joule
Panas spesifik banyu (c) = 4200 J/kg oC
Suhu awal (T1) = 25oC
Dikarepake: Suhu pungkasan (T2)
Solusi:
Q = mc ΔT = mc(T)2 - T1)
Q = panas, m = massa, c = panas spesifik, ΔT = owah-owahan suhu, T1 = suhu awal, T2 = suhu pungkasan
Q = mc(T2 - T1)
42,000 = (0.2)(4200)(T2 - 25)
42,000 = 840 (T2 - 25)
42,000 = 840 T2 - 21,000
42,000 + 21,000 = 840 T2
63,000 = 840 T2
T2 = 63,000/840
T2 = 75oC
- Ngonversi skala suhu
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- Konservasi energi kanggo transfer panas