DOC.
52 347
s3.
Equality
of
action
and reaction
Adding
equations
(6), (7),
and (11),
one
obtains the overall
expression
for the
X-component
of the
ponderomotive
force
acting
on
the
matter
per
unit
volume
in the
form
?£
ÄS
iL
=
div ®+
**
si+
*,w+
**
dAS
x
dZ
ds
09)
+
0
X
~Wx
X +
Q
x
,
n
y
dy
z
d
z
+
7
[aö] +
!
+
i
£
.
Jt
90
ar
c c
x x
This
equation
can
also
be
written
as
^
div
£
+ +
I
dV
S3
+
S)x
div £
+
-
€
08'
x
a;
+
WA
,
«y,)
,
^A
awju «a *)
aaA)
t
t
X X
,
,
..
+ +
^
+
Uz
X
If
one
makes
use
of
Maxwell's
equations to
replace
1
and
Iff
a
+
c
by
curl
f)
and curl
£,
respectively,
a
simple
transformation
yields
ax. ax. dx
as
x 1 z z
dx~l)F
+
Tf
+
TF'^Ti1
(12)
[9]