156
DOC. 4
KINETIC THEORY LECTURE NOTES
dG'
sin
üt/ürfw
*
rod]
-i-A-cosO
•
nc
cos
(p
[24]
dz
4tc
ldG0'
rtc)i
6
dz
1
,UdG'
3
(o.
-
o;))
--tick
ia
3
\2\dz
4X
But
F
must
be of the
same
magnitude
as
for the
middle
cross section,
where
its value
\
\
is
-Inck-
.
Hence,
\
3
dz
\
dG
dz
-
2
-
dz
+
-
-(G0
4a
-
G0')
0
'
1
dG
3
2 dz 4
A.
(G0
-
G0')
G0
-
G0' =
-
0 0
3
dz
[25]
As
we
see,
there
is
a
jump corresponding
to
-
k.
Has
been
proved
by
Kundt
and
Warburg
for
viscosity,
and
by Smoluchowsky
for thermal
conduction.[26]
[p. 10]
Phenomena
at Walls
Owing
to
Finiteness
of
Path
Length
We
assume
that
G
changes linearly
down to
the
lower wall.
There,
but
in
the
gas,
G0'
For the
molecules
flying
off of
the
wall
G0
In the terminal cross-section
as
well
we
must
have
F.
=
--ncA-r-:dGo1
3
dz
On the other
hand,
G-flow
calculated[27]