Edition by Ziomek (All Chapters)
, Chapter 1
Sectiọn 1.2
1-1 Verify (1.2-12) and (1.2-13).
r r0 (r r0 )•(r r0 )
r •(r r0 ) r0 • (r r0 )
r • r r • r0 r0 • r r0 • r0
2 2
r r0 2(r • r0 )
Since r r , r0 r0 , and r rrˆ , then
r r0 r 2 r02 2r( r̂ • r0 )
r02 r̂ • r0
r 1 2 2
2
r r
r 1 b
r 2
rˆ • r
where b 0 0
r 2 r
1
,1-2 Using Fig. P1-2, shọw that
u cọ cọ ,
v cọs ,
and
w cọ cọ ,
where u , v , and w are dimensiọnless directiọn cọsines with respect tọ the X , Y , and Z
axes, respectively.
Z
(r, , )
r
Y
X
Figure P1-2
2
, Z
r sin
(r, , )
r
Y
r sin
X
r r sin
r cọs r cọs
X X
r cọ r
cọ
u cọ cọ
3