Register to reply

Blackbody radiation problem

by LordCalculus
Tags: blackbody, radiation
Share this thread:
LordCalculus
#1
Oct4-10, 02:11 PM
P: 13
1. The problem statement, all variables and given/known data
The average person has 1.4 m^2 of skin at a skin temperature of roughly 306 K. Consider the average person to be an ideal radiator standing in a room at a temperature of 293 K.

a.) Calculate the energy per second radiated by the average person in the form of blackbody radiation. Express you answer in watts. (How do I treat the temperature?)


2. Relevant equations

L=AσT^4

Where A = area; σ = Stefan-Boltzmann constant; T = temperature (in Kelvins).

3. The attempt at a solution

L=(1.4)*(5.670400*10^-8)*(????)^4
Phys.Org News Partner Science news on Phys.org
Scientists develop 'electronic nose' for rapid detection of C. diff infection
Why plants in the office make us more productive
Tesla Motors dealing as states play factory poker
zhermes
#2
Oct4-10, 08:54 PM
P: 1,261
The energy per second radiated will just be that equation with body temperature as T (~310 Kelvin); but note that this isn't the same as the total energy lost per second.
gau_physics
#3
Oct23-10, 08:20 AM
P: 12
Energy radiated per unit time will be given by Stefan-Boltzman law -

dQ/dt = eAσT^4 (σ - Stefan's constant)

but here 'T' is to be taken in Kelvin and not degree celsius.

and also this is not the energy lost since energy lost = (Energy radiated)-(Energy absorbed)

put T value in the equation. For heat radiated T=306 and for absorbed T=293


Register to reply

Related Discussions
Problem from Eisberg: Blackbody Radiation Advanced Physics Homework 5
Blackbody Radiation Problem Introductory Physics Homework 2
About the radiation of blackbody Quantum Physics 4
Blackbody radiation problem Introductory Physics Homework 5
Blackbody Radiation Quantum Physics 3