answers to selected exercises fhmt 7e
ANSWERS TO END-OF-CHAPTER PROBLEMS
Fundamentals of Heat and Mass Transfer (7th Edition)
T.L. Bergman
A.S. Lavine
F.P. Incropera
D.P. DeWitt
CHAPTER 1
1.1
1.3
1.4
1.5
1.6
1.7
1.8
1.9
1.10
1.12
1.13
1.15
1.16
1.18
1.19
1.20
1.21
1.22
1.23
1.24
1.25
1.26
1.27
1.28
1.30
1.31
1.32
1.33
1.34
1.35
1.36
1.37
1.39
1.40
1.41
14.5 W/m2, 58 W
2667 W
4312 W, $8.28/d
–4.35 °C/m
0.10 W/m⋅K
8400 W
(a) 18.5 × 10-6
19,600 W, 120 W
54 mm
16.6 W/m2, 35.9 W
375 mm
110.40°C, 110.24°C
1.1°C
1400 W/m2, 18,000 W/m2
(a) 22.0 W/m2⋅K; (b) 22.12, 0.6
20 W/m2, 20 W/m2, –20 W/m2
4570 W/m2⋅K, 65 W/m2⋅K
6.3 W/m2⋅K
102.5°C
51.8°C, 3203°C
6.3 m/s
0.35 W, 5.25 W
15 mW
(a) 18,405 W; (b) $12,900
254.7 K
4.3 W
0.42, 264 W
(a) 0.32 W/m2⋅K, 0.32 W/m2⋅K, 2.1 W/m2⋅K
(a) 8.1 W; (b) 0.23 kg/h
(a) 0, 144 W, 144 W, 0; 0, 144 W, 144 W, 0; (b) 2.04×105 W/m3; (c) 39.0 W/m2⋅K
(a) 4.86 MW; (b) 9.22 kW; (c) 4.87 MW; (d) 4.87 MW
(a) 300°C; (b) 3.89 MW; (c) 3.19 kW; (d) 3.89 MW
2.41, 312 W, 1.25, 600 W
(a) 0.223 W; (b) 3.44 W
100°C
1.42
1.43
1.45
1.46
1.47
1.48
1.49
1.51
1.52
1.53
1.54
1.55
1.57
1.58
1.59
1.61
1.62
1.63
1.64
1.65
1.66
1.67
1.69
1.70
1.71
1.72
1.73
1.74
1.75
1.76
1.77
1.78
1.79
1.81
1.82
1.83
1.84
1.85
(a) 643 W; (b) 175 h
512°C, 518°C
(a) 0.052°C/s; (b) 48.4°C
375 W, 1.8 × 10-4 W, 0.065 W
300 J, 1800 J, 9000 J
6380 kWh, $1150 or $383
(a) 1.41×10-3 kg/s
(a) 4180 s; (b) 319 K, 359 K; (c) 830 K
(a) 0.0181 m3/s, 4.7 m/s; (b) 5.97 W
840 kW
2360 W/m2, 6100 W/m2
(a) 32.5 kW/m2, 126 kW/m2, 17.6 K/s, 68.6 K/s
(a) 104 K/s; (b) 1251 K
(b) 383°C
63 kg/s
(a) 700 A
132 J/kg⋅K
$0.0032/day
(a) –0.084 K/s; (b) 439 K
3.2 h
(a) 60.6×10-3 kg/s⋅m2, 121 g/m2; (b) 32.3×10-3 kg/s⋅m2
(a) 1010 W; (b) 1310 W
49°C
(a) 7.13×10-3 m3/s; (b) 70°C
(a) 47.0°C or 39.9°C
(a) 86.7°C; (b) 47°C
(a) –0.044 K/s; (b) 230 W, 230 W
(a) 26°C; (b) 4.0 × 10-5 ℓ/s
12.2 W/m2⋅K, 12.2 W/m2⋅°C
(a) 600 K
375 W/m2⋅K
(a) 5500 W/m2; (b) 87.8°C
(a) 5268 W; (b) 41°C
345°C
(a) 84°C
(a) 190.6 W
(a) 153°C; (b) 16 W/m2⋅K
(a) 386 W/m2; (b) 27.7°C; (c) 55%
Fundamentals of Heat and Mass Transfer (7th Edition)
T.L. Bergman
A.S. Lavine
F.P. Incropera
D.P. DeWitt
CHAPTER 1
1.1
1.3
1.4
1.5
1.6
1.7
1.8
1.9
1.10
1.12
1.13
1.15
1.16
1.18
1.19
1.20
1.21
1.22
1.23
1.24
1.25
1.26
1.27
1.28
1.30
1.31
1.32
1.33
1.34
1.35
1.36
1.37
1.39
1.40
1.41
14.5 W/m2, 58 W
2667 W
4312 W, $8.28/d
–4.35 °C/m
0.10 W/m⋅K
8400 W
(a) 18.5 × 10-6
19,600 W, 120 W
54 mm
16.6 W/m2, 35.9 W
375 mm
110.40°C, 110.24°C
1.1°C
1400 W/m2, 18,000 W/m2
(a) 22.0 W/m2⋅K; (b) 22.12, 0.6
20 W/m2, 20 W/m2, –20 W/m2
4570 W/m2⋅K, 65 W/m2⋅K
6.3 W/m2⋅K
102.5°C
51.8°C, 3203°C
6.3 m/s
0.35 W, 5.25 W
15 mW
(a) 18,405 W; (b) $12,900
254.7 K
4.3 W
0.42, 264 W
(a) 0.32 W/m2⋅K, 0.32 W/m2⋅K, 2.1 W/m2⋅K
(a) 8.1 W; (b) 0.23 kg/h
(a) 0, 144 W, 144 W, 0; 0, 144 W, 144 W, 0; (b) 2.04×105 W/m3; (c) 39.0 W/m2⋅K
(a) 4.86 MW; (b) 9.22 kW; (c) 4.87 MW; (d) 4.87 MW
(a) 300°C; (b) 3.89 MW; (c) 3.19 kW; (d) 3.89 MW
2.41, 312 W, 1.25, 600 W
(a) 0.223 W; (b) 3.44 W
100°C
1.42
1.43
1.45
1.46
1.47
1.48
1.49
1.51
1.52
1.53
1.54
1.55
1.57
1.58
1.59
1.61
1.62
1.63
1.64
1.65
1.66
1.67
1.69
1.70
1.71
1.72
1.73
1.74
1.75
1.76
1.77
1.78
1.79
1.81
1.82
1.83
1.84
1.85
(a) 643 W; (b) 175 h
512°C, 518°C
(a) 0.052°C/s; (b) 48.4°C
375 W, 1.8 × 10-4 W, 0.065 W
300 J, 1800 J, 9000 J
6380 kWh, $1150 or $383
(a) 1.41×10-3 kg/s
(a) 4180 s; (b) 319 K, 359 K; (c) 830 K
(a) 0.0181 m3/s, 4.7 m/s; (b) 5.97 W
840 kW
2360 W/m2, 6100 W/m2
(a) 32.5 kW/m2, 126 kW/m2, 17.6 K/s, 68.6 K/s
(a) 104 K/s; (b) 1251 K
(b) 383°C
63 kg/s
(a) 700 A
132 J/kg⋅K
$0.0032/day
(a) –0.084 K/s; (b) 439 K
3.2 h
(a) 60.6×10-3 kg/s⋅m2, 121 g/m2; (b) 32.3×10-3 kg/s⋅m2
(a) 1010 W; (b) 1310 W
49°C
(a) 7.13×10-3 m3/s; (b) 70°C
(a) 47.0°C or 39.9°C
(a) 86.7°C; (b) 47°C
(a) –0.044 K/s; (b) 230 W, 230 W
(a) 26°C; (b) 4.0 × 10-5 ℓ/s
12.2 W/m2⋅K, 12.2 W/m2⋅°C
(a) 600 K
375 W/m2⋅K
(a) 5500 W/m2; (b) 87.8°C
(a) 5268 W; (b) 41°C
345°C
(a) 84°C
(a) 190.6 W
(a) 153°C; (b) 16 W/m2⋅K
(a) 386 W/m2; (b) 27.7°C; (c) 55%