4.2. An average person generates heat at a rate of 84W while resting in a room at T-. Assuming one- quarter of this heat is lost from the head and taking the emissivity of the skin to be 0.9, determine the average surface temperature of the head when it is not covered. The head can be approximated as a 30 cm-diameter sphere, and the interior surfaces of the room can be assumed to be at the room temperature. The surface temperature can be guessed at 40°C for the evaluation of the properties and h. g=9.81 m/s?, o=5.67x10³ W/m²K* Group 4,5,6: T-= 26°C Нead Air T. = 25°C D= 30 cm 60=3 Good luck...

4.2. An average person generates heat at a rate of 84W while resting in a room at T-. Assuming one- quarter of this heat is lost from the head and taking the emissivity of the skin to be 0.9, determine the average surface temperature of the head when it is not covered. The head can be approximated as a 30 cm-diameter sphere, and the interior surfaces of the room can be assumed to be at the room temperature. The surface temperature can be guessed at 40°C for the evaluation of the properties and h. g=9.81 m/s?, o=5.67x10³ W/m²K* Group 4,5,6: T-= 26°C Нead Air T. = 25°C D= 30 cm 60=3 Good luck...

Principles of Heat Transfer (Activate Learning with these NEW titles from Engineering!)

8th Edition

ISBN:9781305387102

Author:Kreith, Frank; Manglik, Raj M.

Publisher:Kreith, Frank; Manglik, Raj M.

Chapter5: Analysis Of Convection Heat Transfer

Section: Chapter Questions

Problem 5.51P

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