Jawaban Soal Asas Black (Post 12 Feb 2013)

1. Diketahui :
T₂=20⁰C
m₂ = 2000g = 2kg
T₁=90⁰C
T_c=62⁰C
c_1,2 = 4200 J/Kg⁰C

Ditanya :
m₁ = ?

Jawab :
Q₁ = Q₂
m_{1 .}  c_{1 .} (T₁-Tc)= m_{2 .} c_{2 .} (T_c-T₂)
m_{1 .}  4200 J/Kg⁰C _. (90⁰C-62⁰C)= 2kg _.  4200 J/Kg⁰C _. (62⁰C-20⁰C)
m_{1 .} 4200 J/Kg⁰C _. (28⁰C)= 2kg _. 4200 J/Kg⁰C _. (42⁰C)
m_{1  .} (28⁰C)= 2kg _.  (42⁰C)
m_{1 .} (28⁰C)= 84kg⁰C
m₁  = 84kg⁰C /  28⁰C
m₁ = 3kg

2.Diketahui :
T₂=20⁰C
m₁ = 4kg
T₁=100⁰C
T_c=52⁰C
c_1,2 = 4200 J/Kg⁰C

Ditanya :
m₂ = ?

Jawab :
Q₁ = Q₂
m_{1 .} c_{1 .} (T₁-Tc)= m_{2 .} c_{2 .} (T_c-T₂)
4kg _. 4200 J/Kg⁰C _. (100⁰C-52⁰C)= m_{2 .} 4200 J/Kg⁰C _. (52⁰C-20⁰C)
4kg _. 4200 J/Kg⁰C _. (48⁰C)= m_{2 .} 4200 J/Kg⁰C _. (32⁰C)
4kg  _. (48⁰C)= m_{2 .} (32⁰C)
4kg  _. (48⁰C)= 32⁰C . m₂
m₂  = 4kg _. (48⁰C) /  32⁰C
m₂  = 6kg


3. Diketahui :
T₂=30⁰C
m₂ = 2kg
T₁=60⁰C
m₁ = 2Kg
c_1,2 = 4200 J/Kg⁰C

Ditanya :
T_c=.....⁰C

Jawab :
Q₁ = Q₂
m_{1 .} c_{1 .} (T₁-Tc)= m_{2 .} c_{2 .} (T_c-T₂)
2Kg _. 4200 J/Kg⁰C _. (60⁰C-Tc⁰C)= 2kg _. 4200 J/Kg⁰C _. (Tc⁰C-30⁰C)
2Kg _.  (60⁰C-Tc⁰C)= 2kg _.(Tc⁰C-30⁰C)
120Kg⁰C-2kgTc⁰C= 2kg Tc⁰C-60kg⁰C 
120Kg⁰C + 60⁰kgC = 2kg Tc⁰C + 2kgTc⁰C
180Kg⁰C = 4Tc⁰kg
Tc = 180Kg⁰C / 4kg
Tc = 45⁰C

4. Diketahui :
T₂=10⁰C
m₂ = 30kg
T₁=90⁰C
m₁ = 10Kg
c_1,2 = 4200 J/Kg⁰C

Ditanya :
T_c=.....⁰C

Jawab :
Q₁ = Q₂
m_{1 .} c_{1 .} (T₁-Tc)= m_{2 .} c_{2 .} (T_c-T₂)
10Kg _. 4200 J/Kg⁰C _. (90⁰C-Tc⁰C)= 30kg _. 4200 J/Kg⁰C _. (Tc⁰C-10⁰C)
10Kg _. (90⁰C-Tc⁰C)= 30kg _.(Tc⁰C-10⁰C)
900Kg⁰C-10kgTc⁰C= 30kg Tc⁰C-300kg⁰C
900Kg⁰C + 300⁰kgC = 30kg Tc⁰C + 10kgTc⁰C
1200Kg⁰C = 40Tc⁰kg
Tc = 1200Kg⁰C / 4kg
Tc = 30⁰C


5. Diketahui :
T₂=10⁰C
m₁ = 150kg
T₁=90⁰C
T_c=40⁰C
c_1,2 = 4200 J/Kg⁰C

Ditanya :
m₂ = ?

Jawab :
Q₁ = Q₂
m_{1 .} c_{1 .} (T₁-Tc)= m_{2 .} c_{2 .} (T_c-T₂)
150kg _. 4200 J/Kg⁰C _. (90⁰C-40⁰C)= m_{2 .} 4200 J/Kg⁰C _. (40⁰C-10⁰C)
150kg _. 4200 J/Kg⁰C _. (50⁰C)= m_{2 .} 4200 J/Kg⁰C _. (30⁰C)
150kg _. (50⁰C)= m_{2 .} (30⁰C)
150kg _. (50⁰C)= 30⁰C . m₂
m₂ = 150kg _. (50⁰C) / 30⁰C
m₂ = 250kg


6. Diketahui :
T₂=10⁰C
m₂ = 0,52kg
T₁=90⁰C
m₁ = 0,1Kg
c₁ = 380 J/Kg⁰C
c₂ = 4200 J/Kg⁰C

Ditanya :
T_c=.....⁰C

Jawab :
Q₁ = Q₂
m_{1 .} c_{1 .} (T₁-Tc)= m_{2 .} c_{2 .} (T_c-T₂)
0,1Kg _.  380 J/Kg⁰C _. (90⁰C-Tc⁰C)= 0,5kg _. 4200 J/Kg⁰C _. (Tc⁰C-10⁰C)
38 J/Kg⁰C _. (90⁰C-Tc⁰C)= 2100J/⁰C  _.(Tc⁰C-10⁰C)
3420Kg⁰C-38kgTc⁰C= 2100kg Tc⁰C- 21000kg⁰C
3420Kg⁰C + 21000⁰kgC = 2100kg Tc⁰C + 38kgTc⁰C
24420Kg⁰C = 2138Tc⁰kg
Tc = 24420Kg⁰C / 2138kg
Tc = 11,4⁰C

 7. Diketahui : T₂=10⁰C
m₂ = 250g = 0,25 Kg
T₁=100⁰C
m₁ = 200Kg = 0,2 Kg
c_1,2 = 4200 J/Kg⁰C

Ditanya :
T_c=.....⁰C

Jawab :
Q₁ = Q₂
m_{1 .} c_{1 .} (T₁-Tc)= m_{2 .} c_{2 .} (T_c-T₂)
0,2Kg _. 4200 J/Kg⁰C _. (100⁰C-Tc⁰C)= 0,25kg _. 4200 J/Kg⁰C _. (Tc⁰C-10⁰C)
0.2Kg _. (100⁰C-Tc⁰C)= 0,25kg _.(Tc⁰C-10⁰C)
20Kg⁰C-0,2kgTc⁰C= 0,25kg Tc⁰C - 2,5kg⁰C
20Kg⁰C + 2,5⁰kgC = 0,25kg Tc⁰C + 0,2kgTc⁰C
22,5Kg⁰C = 0,45Tc⁰kg
Tc = 22,5Kg⁰C / 0,45kg
Tc = 50⁰C