(2) Suppose a person is covered head to foot by wool clothing with average thickness of 2 cm and is transferring energy of 9000 joules by conduction through the clothing for 3 minutes. What is the temperature difference across the clothing, given the surface area is 1.8m2? (Given: Thermal conductivity of wool is 0.04 W/mK) The difference in temperature=

(2) Suppose a person is covered head to foot by wool clothing with average thickness of 2 cm and is transferring energy of 9000 joules by conduction through the clothing for 3 minutes. What is the temperature difference across the clothing, given the surface area is 1.8m2? (Given: Thermal conductivity of wool is 0.04 W/mK) The difference in temperature=

Physics for Scientists and Engineers: Foundations and Connections

1st Edition

ISBN:9781133939146

Author:Katz, Debora M.

Publisher:Katz, Debora M.

Chapter19: Temperature, Thermal Expansion And Gas Laws

Section: Chapter Questions

Problem 39PQ

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The thermal conductivities of human tissues vary greatly. Fat and skin have conductivities of about 0.20 W/m K and 0.020 W/m K, respectively, while other tissues inside the body have conductivities of about 0.50 W/m K. Assume that between the core region of the body and the skin sin face lies a skin layer of 1.0 mm, fat layer of 0.50 cm, and 3.2 cm of other tissues. (a) Find the R-factor for each of these layers, and the equivalent R-factor for all layers taken together, retaining two digits. (b) Find the rate of energy loss when the core temperature is 37C and the exterior temperature is 0C. Assume that both a protective layer of clothing and an insulating layer of unmoving air a absent, and a body area of 2.0 m2.
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