Heat Flow between a Human and a Chair
Heat Flow between a Human and a Chair
This Demonstration shows the equilibration between two objects at different temperatures in thermal contact with one another. In this case, the objects are a human and a chair of equal mass.
You can vary the temperature and the heat capacity of the chair to determine the time it takes to reach thermal equilibrium, the equilibrium temperature and the total entropy change. The three relevant equations are:
thermal equilibrium temperature: =++,
T
eq
C
1
T
1
C
2
T
2
C
1
C
2
entropy: ,
S=ln+(+)+ln+(+)
C
1
C
1
T
1
C
2
T
2
T
1
C
1
C
2
C
2
C
1
T
1
C
2
T
2
T
2
C
1
C
2
time=(-)
C
p,2
T
eq
d
barrier
d
2
ρ
2
k
barrier
T
2
T
1
where represents heat capacity and ρ represents density, the subscripts 1 and 2 stand for the human and the chair, is the thickness of the skin barrier and is the thermal conductivity of the skin barrier.
C
d
barrier
k
barrier