A wooden sphere of diameter 5 cm is initially at a uniform temperature of 21 °C. Its surface temperature is suddenly raised to 83 °C. The thermal conductivity and thermal diffusivity of the wood are 0.15 W/m K and 0.82 x 10-7 m^2/s, respectively. a) Calculate the temperature 2 cm beneath the surface of the sphere 30 min after the sudden increase in temperature. b) Calculate the energy gained by the sphere during this time.
A wooden sphere of diameter 5 cm is initially at a uniform temperature of 21 °C. Its surface temperature is suddenly raised to 83 °C. The thermal conductivity and thermal diffusivity of the wood are 0.15 W/m K and 0.82 x 10-7 m^2/s, respectively. a) Calculate the temperature 2 cm beneath the surface of the sphere 30 min after the sudden increase in temperature. b) Calculate the energy gained by the sphere during this time.
Elements Of Electromagnetics
7th Edition
ISBN:9780190698614
Author:Sadiku, Matthew N. O.
Publisher:Sadiku, Matthew N. O.
ChapterMA: Math Assessment
Section: Chapter Questions
Problem 1.1MA
Related questions
Question
A wooden sphere of diameter 5 cm is initially at a uniform temperature of 21 °C. Its surface
temperature is suddenly raised to 83 °C. The thermal conductivity and thermal diffusivity of
the wood are 0.15 W/m K and 0.82 x 10-7 m^2/s, respectively.
a) Calculate the temperature 2 cm beneath the surface of the sphere 30 min after the sudden increase in temperature.
b) Calculate the energy gained by the sphere during this time.

Transcribed Image Text:T(0,1)-T,
T-T,
0.8
0.7
0.6
1.0
20.9
Q(oc)
1.0
0.01
0.007
0.005
0.004
0.003
0.002
0.5
0.4
0.3
0.2
0.001
0.5
0.4
0.1
0.07
0.05
0.04
0.03
0.02
1.0
T(r.1)-T, 0.9
T(0.1)-T,
0.3
0.2
0.1
0
0.5 1.0
0
10-5
0.8 0.4
0.7 0.5
0.6
0.6
0.5
0.4 0.7
0.3 0.8
0.2 0.9
0.1
1.0
0
0.01
Bi=
r/R=0.2
THAN
aR
T
15 2.0
10-4
0.1
2.5 3 4 5 6 7 8 9 10
1.0
Bi= 0.001
0.002-
0.005.
0.01-
10-3
Bi=
02-
0.02
0.05
10 Bi 100
20
10-2 10-1
30 40
1
70
10
103
104
Bf Fo=to²/kpc
Figure 3- Dimensionless Transient Temperatures and Heat Transfer for a Sphere
Bi=
DR
noi
110 130 170 210
Fo-tk
pcR²
102
250
Expert Solution

This question has been solved!
Explore an expertly crafted, step-by-step solution for a thorough understanding of key concepts.
Step by step
Solved in 4 steps with 31 images

Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, mechanical-engineering and related others by exploring similar questions and additional content below.Recommended textbooks for you

Elements Of Electromagnetics
Mechanical Engineering
ISBN:
9780190698614
Author:
Sadiku, Matthew N. O.
Publisher:
Oxford University Press

Mechanics of Materials (10th Edition)
Mechanical Engineering
ISBN:
9780134319650
Author:
Russell C. Hibbeler
Publisher:
PEARSON

Thermodynamics: An Engineering Approach
Mechanical Engineering
ISBN:
9781259822674
Author:
Yunus A. Cengel Dr., Michael A. Boles
Publisher:
McGraw-Hill Education

Elements Of Electromagnetics
Mechanical Engineering
ISBN:
9780190698614
Author:
Sadiku, Matthew N. O.
Publisher:
Oxford University Press

Mechanics of Materials (10th Edition)
Mechanical Engineering
ISBN:
9780134319650
Author:
Russell C. Hibbeler
Publisher:
PEARSON

Thermodynamics: An Engineering Approach
Mechanical Engineering
ISBN:
9781259822674
Author:
Yunus A. Cengel Dr., Michael A. Boles
Publisher:
McGraw-Hill Education

Control Systems Engineering
Mechanical Engineering
ISBN:
9781118170519
Author:
Norman S. Nise
Publisher:
WILEY

Mechanics of Materials (MindTap Course List)
Mechanical Engineering
ISBN:
9781337093347
Author:
Barry J. Goodno, James M. Gere
Publisher:
Cengage Learning

Engineering Mechanics: Statics
Mechanical Engineering
ISBN:
9781118807330
Author:
James L. Meriam, L. G. Kraige, J. N. Bolton
Publisher:
WILEY