Homework 1 Solutions

048 caloriess m is total mass which for a person is

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Unformatted text preview: pts] The human body has an average temperature of 310 K (98.6ºF) Assume the skin is a perfect radiator and absorber, and that you are standing in a room with a constant temperature of 293 K (68ºF). (a) [5 pts] What is the peak wavelength λmax of your thermal spectrum? In what part of the electromagnetic spectrum is this found? Wein’s displacement law: λpkT ≈ 3000 µm ­K => λpk = 9.7 µm – this is in the thermal infrared (b) [10 pts] How much power (in kilowatts kW) do you radiate in the form of blackbody radiation? (Hint: you’ll need to estimate a typical body surface area) Body area – assume 2 m tall and 0.5 m across with 2 sides (a very planar person!) => 2 m2 Blackbody power = AσT4 = (2 m2)(5.67x10 ­8 W/m2/K4)(310 K)4 = 1047 W or 1.0 kW (c) [5 pts] How much power (in kilowatts kW) do you absorb from the environment, and what is your net...
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This document was uploaded on 02/26/2014 for the course PHYS 160 at UCSD.

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