You have been asked to cook a 6 kg joint of beef in a conventional oven preheated to 200°C. The joint of meat is roughly spherical and therefore the joint can be modelled as a uniform sphere. i) Normal cooking times for beef state you should cook for at least 60 minutes per kg plus an additional 30 minutes. Estimate the normal cooking time for the beef. ii) Estimate the heat flux into the joint needed to raise the temperature of the joint from 25 °C to a minimum cooked temperature of 70 °C. Given: a. The heat capacity for beef is: 1. 67 kJ/kg/K. b. The density of beef is 1033 k/m'. iii) Assuming only heat transfer occurs through a solid, calculate the rate of accumulation of heat in the meat. iv) Derive a simple expression for the temperature profile in the radial direction through the meat. Given: a. The thermal conductivity of the beef is 0.45 W/m/K. v) Calculate the minimum time needed to reach the minimum temperature of 70 °C using your expression. vi) Compare your answer in part v) with that in part i) and comment on your observations.

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
icon
Related questions
Question
You have been asked to cook a 6 kg joint of beef in a conventional oven
preheated to 200°C. The joint of meat is roughly spherical and
therefore the joint can be modelled as a uniform sphere.
i) Normal cooking times for beef state you should cook for at least 60
minutes per kg plus an additional 30 minutes. Estimate the
normal cooking time for the beef.
ii) Estimate the heat flux into the joint needed to raise the temperature
of the joint from 25 °C to a minimum cooked temperature of 70
°C. Given:
a. The heat capacity for beef is: 1. 67 kJ/kg/K.
b. The density of beef is 1033 k/m'.
iii) Assuming only heat transfer occurs through a solid, calculate the
rate of accumulation of heat in the meat.
iv) Derive a simple expression for the temperature profile in the radial
direction through the meat. Given:
a. The thermal conductivity of the beef is 0.45 W/m/K.
v) Calculate the minimum time needed to reach the minimum
temperature of 70 °C using your expression.
vi) Compare your answer in part v) with that in part i) and comment
on your observations.
vii) The meat is actually cooked in a fan assisted convection oven and
is observed to cook at a much quicker rate than that calculated
either by part i) or part v). What does this tell you about the
mode of heat transfer and the controlling mechanisms?
Transcribed Image Text:You have been asked to cook a 6 kg joint of beef in a conventional oven preheated to 200°C. The joint of meat is roughly spherical and therefore the joint can be modelled as a uniform sphere. i) Normal cooking times for beef state you should cook for at least 60 minutes per kg plus an additional 30 minutes. Estimate the normal cooking time for the beef. ii) Estimate the heat flux into the joint needed to raise the temperature of the joint from 25 °C to a minimum cooked temperature of 70 °C. Given: a. The heat capacity for beef is: 1. 67 kJ/kg/K. b. The density of beef is 1033 k/m'. iii) Assuming only heat transfer occurs through a solid, calculate the rate of accumulation of heat in the meat. iv) Derive a simple expression for the temperature profile in the radial direction through the meat. Given: a. The thermal conductivity of the beef is 0.45 W/m/K. v) Calculate the minimum time needed to reach the minimum temperature of 70 °C using your expression. vi) Compare your answer in part v) with that in part i) and comment on your observations. vii) The meat is actually cooked in a fan assisted convection oven and is observed to cook at a much quicker rate than that calculated either by part i) or part v). What does this tell you about the mode of heat transfer and the controlling mechanisms?
Expert Solution
steps

Step by step

Solved in 3 steps

Blurred answer
Knowledge Booster
Conduction
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.
Similar questions
  • SEE MORE QUESTIONS
Recommended textbooks for you
Elements Of Electromagnetics
Elements Of Electromagnetics
Mechanical Engineering
ISBN:
9780190698614
Author:
Sadiku, Matthew N. O.
Publisher:
Oxford University Press
Mechanics of Materials (10th Edition)
Mechanics of Materials (10th Edition)
Mechanical Engineering
ISBN:
9780134319650
Author:
Russell C. Hibbeler
Publisher:
PEARSON
Thermodynamics: An Engineering Approach
Thermodynamics: An Engineering Approach
Mechanical Engineering
ISBN:
9781259822674
Author:
Yunus A. Cengel Dr., Michael A. Boles
Publisher:
McGraw-Hill Education
Control Systems Engineering
Control Systems Engineering
Mechanical Engineering
ISBN:
9781118170519
Author:
Norman S. Nise
Publisher:
WILEY
Mechanics of Materials (MindTap Course List)
Mechanics of Materials (MindTap Course List)
Mechanical Engineering
ISBN:
9781337093347
Author:
Barry J. Goodno, James M. Gere
Publisher:
Cengage Learning
Engineering Mechanics: Statics
Engineering Mechanics: Statics
Mechanical Engineering
ISBN:
9781118807330
Author:
James L. Meriam, L. G. Kraige, J. N. Bolton
Publisher:
WILEY